ES-NiroSan® - Technical Data

  • 1.
  • 1.1
  • 1.2
  • 1.2.1
  • 1.2.2
  • 1.2.3
  • 1.2.3
  • 1.3
  • 1.3.1
  • 1.3.2
  • 2
  • 2.1
  • 2.1.1
  • 2.1.2
  • 2.1.3
  • 2.1.4
  • 2.2
  • 2.2.1
  • 2.2.2
  • 2.2.3
  • 2.2.4
  • 2.2.5
  • 2.2.6
  • 2.2.7
  • 2.2.8
  • 2.2.9
  • 2.2.10
  • 2.2.11
  • 2.2.12
  • 2.2.13


1. System description and possible uses

1.1 Areas of use

Modern building equipment and appliances make great demands of the utilities supply systems. Safety, durability, hygiene and not least cost-efficiency are the criteria by which pipe systems are judged and deployed. The SANHA® NiroSan® press-fit system is a DVGW-tested crimping system that complies with all market requirements (DVGW DW 851 AU- 2127). The system components, i.e. pipes, fittings and accessories, are matched to each other and exceptionally well suited to use in drinking water installations for cold and hot water.

In addition the system is suitable for:

  1. re-processed water, softened water, partially and fully desalinated water, including also: de-carbonised water, de-mineralised water, osmosis water, distilled water,
  2. compressed air, free of oil, up to 16 bar (for technical compressed air - containing oil - on request),
  3. steam condensate, both as dry and as wet condensate piping up to 130°C or 16 bar,
  4. water containing soap (clilavitt) pH 12, very alkaline, water containing ethylene glycol (anti-freeze), water containing alcohol (windscreen washer fluid), solar power systems containing a water/glycol mix for long-term exposure to 120°C – for temperatures up to 200°C on request,
  5. service and rain water utilisation systems,
  6. heating systems,
  7. district heating systems, directly run up to 200°C on request,
  8. pipelines for conveying bulk materials,
  9. pipelines for noble gases and technical gases,
  10. pipelines for conveying corrosive water,
  11. pressurised drainage of roofs and parts of buildings,
  12. pipelines for industrial facilities.

If any special tasks relating to conveying liquids, corrosive fluids or technical gases or if, in general, upcoming challenges in the industrial field need to be solved, the suitability of SANHA® NiroSan® press-fit systems ought to be checked in each individual case. In such cases please contact our technical customer support team.

Safety, durability and hygiene are guaranteed by:

  • SANHA® NiroSan® system fittings:
    Made of non-corroding steel, material no. 1.4404, 1.4571, 1.4408
  • Moulded part seal:
    EPDM, peroxide cross-linked, suitable for drinking
    water as per the recommendations on contact with drinking water from the Federal Office of Public Health.
  • SANHA® NiroSan® system-based pipes:
    material 1.4404
  • Connection technique:
    crimping pipe and fitting together at three levels using appropriate crimping tools ahead of, towards and up to a measurement of 54mm, including behind the seal.


1.2 System description.

The SANHA® NiroSan® press-fit system consists of the following system components.

  1. SANHA® NiroSan® system pipe
    Stainless steel pipes (DVGW – W 541) material 1.4404. The pipes are bright annealed, stress relieved and solution annealed. There is an upper limit on their rigidity in order to ensure adequate and permanent deformation of fitting and pipe when using appropriate standard crimping tools and dies recommended by SANHA®.

  2. SANHA® NiroSan® crimp fittings and threaded parts,
    material number 1.4404 (shaped parts) , 1.4571 (threaded parts) and 1.4408 (precision-cast stainless steel parts).

    The crimp fittings are pickled for corrosion-related reasons, bright, solution and soft annealed and stress relieved. The crimp fitting's degree of hardness thus becomes ostensibly that of the SANHA® NiroSan® system pipe and secure, permanent deformation during the crimping process is ensured.

  3. Seal
    Sealing rings made of EPDM, peroxide cross-linked and tested in line with the recommendations on contact with drinking water from the Federal Office of Public Health are inserted into the fitting as standard at the factory (9000 range). This high-quality polymer is particularly well-suited to use in drinking water pipeline systems up to a maximum operating temperature of 120°C.

    For higher temperatures (max. 200°C) and corrosive media SANHA® NiroSan® system fittings with seals made of special elastomer are available (18000 range). In terms of the area of use, please contact our technical customer support team.

    If for particular areas of use seals and fittings are required to be absolutely free of silicon (paint shops, automotive industry), then SANHA® NiroSan® system fittings with special FPM seals (19000 range) are available for this.

  4. Tool
    When designing and developing the SANHA® NiroSan® press-fit system, the sleeve shape was defined in such a way that it is possible to use dies and presses already present on the market (cf.1.2.4.). For anyone working with these systems there is generally therefore no need to invest in new tools.

    SANHA®, however, recommends the ECO 301 electronic SANHA® press with SANHA® dies and press collars (cf. also table 3). In combination with the SANHA®-specific eight-edge profile (12-35 mm) or nine-edge profile (42-54 mm) and especially with the SANHA® profile for dimensions 76.1 to 108mm this produces a very round crimp that does little harm to the material.

1.2.1 Working with stainless steel

Drinking water that comes into contact with other substances, such as e.g. pipeline materials, container materials etc., may react chemically with them. If, for example, the pipeline is made of copper, then as a result of this reaction copper ions in the drinking water dissolve. Lead, nickel etc. can get into drinking water from fittings and apparatus components. How much gets in depends on the length of time that is available for the reaction processes - i.e. on how long the water remains in the pipeline - and on the condition of the water.

Type and maximum permitted volumes (limits) in relation to toxic substances are stipulated in the Drinking Water Directive (TrinkwV). In order to ensure that these levels are not exceeded, attention must be paid when selecting materials to the utilisation criteria set out in DIN 50930-6. Pursuant to these there is no restriction on the area of use for non-corroding steels as defined by DVGW worksheets W 534 / W 541. The SANHA® NiroSan® press-fit system can thus be used without restriction in all drinking waters.

If the SANHA® NiroSan® press-fit system is to be used in the industrial sector for any of a wide array of media, in swimming pools or for conveying seawater, we ask that in respect of exposure to potential corrosion you please speak to our technical customer support team. When planning and assembling any systems, you should as a general principle avoid any high concentrations of chloride, which could affect the system from the outside.

The main advantages of the stainless steel grades used in the SANHA® NiroSan® press-fit system are:

a) Extreme resistance to corrosion

b) Mechanical strength

c) Permanently smooth surfaces

d) No migration of metal ions

e) Excellent hygienic qualities

f) Long service life

g) Hardness of stainless steel

a) Stainless steel's resistance to corrosion
Due to its integral alloy elements, when it comes into contact with water that contains oxygen, i.e. drinking water, stainless steel forms a passive coating on its surface consisting predominantly of chrome oxide. This coating prevents any further reaction between drinking water and the pipeline material. Regardless of the condition of the drinking water, it is thus impossible for the pipeline material to have any influence on it. Pitting is extremely rare in stainless steel and can only occur if the critical corrosion potential (e.g. through high chloride ion or bromide ion concentrations) is exceeded. If simultaneously put under strain by critical tensile stress, stress-crack corrosion can also occur. Higher temperatures (> 90 ... 100°C) increase any existing risk of corrosion. In order to avoid corrosion damage of this kind, DIN 50930, part 4 therefore recommends for chloride concentrations of over 200 mg/l the use of stainless steels containing molybdenum. Concentrations above this level can in certain circumstances be achieved in stagnating drinking water through local concentration-increasing processes, which is why it generally makes sense to use stainless steels containing molybdenum. The grades of stainless steel used in the SANHA® NiroSan® press-fit system contain molybdenum as an alloy component, thus achieving extreme resistance against pitting and stress-crack corrosion.

The material can be made more susceptible through oxide coatings, tempering colours, incorrect heat treatment (e.g. during welding) and polishing the components, resulting in an increased likelihood of pitting. The same effect is caused by oxidation agents, such as are used, for example, for disinfection, if they are added to drinking water and able to take effect over a relatively long time. Their use is therefore allowed only subject to specific provisos. The use of chlorine oxide as a disinfectant is not permitted under any circumstances.

In the case of the SANHA® NiroSan® press-fit system a permanently watertight pipe connection is achieved by cold forming of the material. This ensures that any risk of making the material more susceptible is avoided. This criterion must also be satisfied by correct assembly of the systems. For example, when separating the pipes it is essential to avoid any impermissible heating up of the interfaces - such as is unavoidable when using cut-off wheels (Flex). Direct contact with the unalloyed steel leads to no passive layer being able to form at the point of contact and thus the material becomes susceptible there. You must therefore not use any tools for separating or deburring the pipes that have previously been used on unalloyed steel. Attention must also be paid to these interactions when storing and transporting the pipes and fittings. Where stainless steels containing molybdenum are worked with correctly the corrosion mechanisms referred to above play no role. Under the operating conditions that arise in drinking water installations the potential for pitting is not reached. In the electrochemical series stainless steel has a somewhat higher potential than copper and much higher than zinc-plated steel. In drinking water installations where on the one hand there exists an electron-conducting link (i.e. generally a metallic-conducting combination) and on the other an ion-conducting link (i.e. generally a combination through an electrolyte such as, e.g., drinking water) between stainless steel and the electrochemical less noble material cathodic/anodic effects can therefore occur. In this process the less noble metal dissolves to the benefit of the more noble stainless steel. This corrosion mechanism is called contact corrosion. The manifestation of contact corrosion is shallow pitting.

The corrosion current created by this mechanism is dependent on the potential difference between the two metals and on the ion-conductivity of the electrolyte (i.e. on the condition of the water). However, the speed at which the less noble metal dissolves is not dependent solely on the level of corrosion current, but rather on the density of the corrosion current (level of corrosion current related to the corroding surface area). In the case of contact with zinc-plated steel it is generally adequate to create a distance between the stainless steel and the zinc-plated steel that is approximately the same as the pipe diameter in order to adequately avoid the ion conductivity of the drinking water. This can be done, for example, using a fitting between the two steels made of gunmetal or brass.

For mixed installations of stainless steel and copper the relationships can be rated much less critically, as the potential difference between copper and stainless steel is minimal. Copper only dissolves at a speed (corrosion current density) of any technical relevance where the copper area is very small in comparison to that of the stainless steel. This is the case, as shown by practical experience, when, for instance, a single copper fitting is built into an extensive stainless steel installation. We know of no scientific literature on any tests as to where the critical area-to-area ratio lies. To be on the safe side in terms of any possible damage caused by contact corrosion between copper and stainless steel the ratio of copper material area (copper, including gunmetal and brass) to stainless area should not be appreciably less than 0.02. The order of the different materials is immaterial. The flow rule familiar from fitting copper and zinc-plated steel together in drinking water pipelines does not therefore need to be considered when combining copper or zinc-plated steel and stainless steel. In heating systems these interrelationships do not apply. The heating water in properly installed and operated heating systems is largely free of oxygen. Without oxygen there is, however, no metal corrosion under the operating conditions of relevance here.

Conclusion: the laboratory tests run to date and in particular existing practical experience have shown that for the materials used no corrosion damage is to be expected from any drinking water or water of a similar composition.

b) Mechanical strength
Stainless steel is very strong. Its tensile strength is at least Rm 550 N/mm2 and proportional limit Rp0.2 240 N/mm2. These levels of strength provide certainty against the pipes and moulded parts bending or becoming physically damaged during assembly, modification or operation of the installations.

c) Surface qualities
Due to its mechanical strength the surface of stainless steel is very hard and highly durable. As a result of these qualities the material suffers, e.g. when highly exposed to particles carried in drinking water, practically no erosion. The smooth surfaces of the stainless steel pipes remain preserved even after longer than average use so that the minimal current loss from the outset and the usage characteristics of the installation remain consistent and unchanged. Stainless steel pipelines look permanently good and are totally maintenance-free. For the architects drawing up the plans stainless steel systems thus offer new creative possibilities.

d) Migration of pipeline materials
Migration of pipeline materials means the absorption of elements of the pipe material as dissolved substances (ions) in the transported medium. In the case of stainless steel components containing molybdenum no migration takes place, because the passive coating on the surface prevents the ions dissolving. Even in the event of longer intervals of stagnation the condition of drinking water is not influenced or changed by dissolving metal ions. The SANHA® NiroSan® press-fit system can therefore – as DIN 50930-6 stresses as well – be used in all drinking waters, regardless of their condition. In the case of other materials (e.g. lead pipelines) it is possible, especially when the water stagnates, for concentrations of heavy metal ions to occur that reach or even exceed the limits stipulated in the Drinking Water Directive.

e) Hygienic qualities of stainless steel
The long-practised use of stainless steel in food processing, food preparation and for medical equipment provides clear proof of this material's harmless qualities in terms of hygiene. In addition to its neutral effect on taste and excellent surface quality, there is another benefit that has become particularly valued in recent times: in terms of microbiological characteristics stainless steel behaves in an inert way. That means that stainless steel surfaces (unlike surfaces of organic materials) provide no support for any microbiological growth. Bacteria, putrefactive agents and spores, etc. thus have no chance to grow on stainless steel surfaces. This positive property of stainless steel directly benefits drinking water and generally makes any disinfection measures superfluous in stainless steel drinking water systems.

f) Long service life of stainless steel
The SANHA® NiroSan® press-fit system made of stainless steel, material no. 1.4404/1.4571/1.4408 has an excellent level of endurance. It is mechanically very strong and is very resistant to corrosion. Particles carried with the drinking water (e.g. grains of sand washed into it) cause practically no abrasion or erosion. Meanwhile the smooth surfaces of the stainless steel pipe walls make it difficult for any substances dissolved in the drinking water to deposit themselves and consequently hardly any incrustations are able to form. The carefully selected alloy components also guarantee that the systems remain stable and watertight for the long term. The special properties of the stainless steel ensure that even after relatively long use no metal ions dissolve and no abrasion or reduction in the thickness of the pipe walls occurs. Drinking water installations made from the SANHA® NiroSan® press-fit system are hygienic, stable, reliable, do not impair the condition of the water and can also be deployed without any harm as mixed installations.

g) Hardness of stainless steel
As the SANHA® NiroSan® press-fit system offers for those working with it the benefit of being able to use standard and possibly already existing presses and dies, although stainless steel is an extremely 'hard' material with relatively high elastic recovery, both the SANHA® NiroSan® system pipe and the SANHA® NiroSan® system fittings are bright, solution and soft annealed and stress relieved. Through exact adherence to the degree of hardness prescribed at the factory for the system components a reliable and permanently watertight joint is achieved even when using different presses and dies.

1.2.2 System components

For formulating tender document texts table 1 provides an overview of the components of the SANHA® NiroSan® press-fit system. Finished tender document texts are available on diskette in the DATANORM 4.0 format and can be requested from our field advisers.

SANHA® NiroSan® press-fit system

 

Pipe material

SANHA® NiroSan® system pipe

Non-corroding steel, material no. 1.4404

Moulded part material

SANHA® NiroSan® press fittings

Non-corroding steel, material no. 1.4404, 1.4408

Seal material

EPDM, peroxide cross-linked / special elastomer

Connection technique

SANHA® NiroSan® press-fit system

Area of use

See point 1.1

Operating temperature range

EPDM: -30 0C ... 120 0C (9000 range) or

FPM: -20 0C ... 200 0C (18000 & 19000 ranges)

Operating pressure

See table 5

Licences (pipes and moulded parts)

DVGW system approval: DW – 8511AU2127

SVGW system approval: 9912 – 4179

ÖVGW system approval: W – 1.287

Advantages of the system:

• universally usable, wide range

• fast, easy assembly

• robust, reliable design

• especially resistant to corrosion

• seals made of KTW-approved elastomer

• all components made of stainless steel

Table 1: Overview of SANHA® NiroSan® system components

1.2.3 Connection method

What makes the SANHA® NiroSan® press fittings special is the way in which the sleeve sockets are designed and made, thus making them reliable to work with and ensuring watertight, permanent joints. Pressing takes place up to and including 54mm in three levels - in front of the crimp, on the crimp and behind the crimp (see picture 2). This ensures high pull-out resistance. Any hydraulic shocks occurring in the installation thus represent practically no risk to the soundness of the system. Using a template (catalogue no. 4981), the insertion depth of the pipe end (cut to length at right angles and cleanly deburred) is marked, then, being rotated slightly, pushed into the sleeve socket (see also the relevant assembly information). The permanently watertight connection is produced by pressing together. The very fast pressing together creates a permanent, form-locked and force-locked joint.

In combination with the SANHA® -specific eight-edge profile (12 mm to 35 mm) or nine-edge profile (42 mm and 54 mm) or the special profile for dimensions over 54 mm (76.1 mm to 108 mm) a very round crimp is produced that does little harm to the material.

For dimensions above 54 mm diameter there are no standard presses available on the market that generate sufficient force to crimp stainless steel at 3 levels, it being 2.5 times harder than copper. Here therefore due to our expectations the presses available on the market should be approved and, from a technical point of view, crimping at 2 levels favoured.

1.2.4 Suitable and recommended crimping tools

Press fitting, pipe, die and press are always matched together in such a way that the interplay of these four components produces permanently watertight, adequately pressure-resistant joints. That, however, means on the other hand that the tolerances to be coped with by the system must spread themselves over the components. In the case of the press fitting and the pipes SANHA® provides for very narrow production tolerances. That makes it especially important that die and press function perfectly. Worn dies in particular and also presses that no longer work perfectly (because, for example, the press hub has shifted over time) can thus lead to insufficiently sound joints.

Both dies, which necessarily become worn in the course of operation, and presses must therefore be subjected to regular checks to ensure that they are working correctly. All dies and presses should as a basic principle be serviced at least once a year. In order to achieve a permanent, sound crimp, it is possible up to and including the dimension of 54 mm to use crimping tools that generate in the pressing process linear forming pressure of at least 30 kN. If any appreciably higher levels of linear forming pressure arise (over 33 kN), the dies could become damaged (beware, risk of injury!).

For crimping the SANHA® NiroSan® press fitting with the SANHA® NiroSan® system pipe the presses and dies listed in table 2 can be used if they are in perfect condition, the inspections and maintenance intervals stipulated by the manufacturer have been adhered to and they are used in accordance with the manufacturers' operating instructions. Every SANHA® press has a round servicing label. The marking on the label indicates when the machine next has to be sent in for maintenance to Novopress or to a specialist workshop authorised by Novopress. Where maintenance is carried out regularly (once a year) the warranty is extended to 3 years.

Servicing label

1.3 Construction parts range 

1.3.1 SANHA® NiroSan® system pipes

In accordance with the required flow rates / the nominal widths determined pursuant to DIN 1988-3, you are able to select from the following range of pipes:

Nominal width DN

DN

Outer Ø

mm

Wall thicknessmm

Inner Ø

cm²

12

15,0

1,0

13,0

15

18,0

1,0

16,0

20

22,0

1,2

19,6

25

28,0

1,2

25,6

32

35,0

1,5

32,0

40

42,0

1,5

39,0

50

54,0

1,5

51,0

65

76,1

2,0

72,1

80

88,9

2,0

84,9

100

108,0

2,0

104,0

 

Inner cross-section cm²

Pipe weight empty kg m-1

Pipe weight filled with water kg m-1

1,33

0,351

0,484

2,01

0,427

0,628

3,02

0,627

0,928

5,15

0,807

1,322

8,04

1,261

2,066

11,95

1,525

2,719

20,43

1,977

4,020

40,83

3,720

7,803

56,61

4,363

10,024

84,95

5,321

13,816

 

the SANHA® NiroSan® system pipes are made of stainless steel, material no. 1.4404, and supplied in 6-metre lengths. The pipes' lengthways seams are plasma arc welded, consequently ensuring that the pipe is absolutely watertight, very mechanically strong and protected from corrosion as required around the welded seam as well. The inner seam of the pipe is also smoothed so that no deposits are able to form at this susceptible spot. The pipes are bright, solution and soft annealed and stress relieved and have a defined maximum strength in order to create optimum preconditions for reliable, secure crimping.

1.3.2 SANHA® NiroSan® press fittings

The press fitting moulded parts are made of molybdenum-stabilised stainless steel piping, material no. 1.4404 or from precision-cast stainless steel, material no. 1.4408. The threaded parts are bonded to the base body by plasma arc welding and are made of stainless steel, material no. 1.4571. This material largely matches the quality of 1.4404, but in order to improve ease of machining additionally contains a maximum of 0.8 per cent by weight of titanium as an alloy component. This thus ensures for these parts too the high standard of quality of the SANHA® NiroSan® products.

2. Planning guidance

2.1 General planning guidance

Along with its components, the SANHA® NiroSan® press-fit system is approved for and can be used in drinking water systems, for cold and hot pipelines and for risers and distribution lines inside and outside buildings, but not, however, for direct laying in the earth. DIN 1988, parts 1 to 7 are applicable for the planning of drinking water installations. DIN 1988, part 8 is applicable for their operation. For the permissible operating conditions refer to table 5.

Pipe outer diameter

15 ... 22

mm

28 ... 35

mm

42 ... 54

mm

76.1 ... 108

mm

Nominal pressure (PN)

40

25

16

10

Max. operating temperature

 

 

 

 

with EPDM seal (9000 range)

120 0C

120 0C

120 0C

120 0C

with FPM seal (18000 range)

200 0C

200 0C

200 0C

200 0C

 

2.1 Dual cutting edge ring screw fitting

In most cases where a screw fitting is required benefits are achieved by using the dual cutting edge ring. As the union nut is tightened, initially the front cutting edge grips into the pipe and as it is tightened further the second cutting edge does so. Once the functional incisions of the cutting edges have finished, any further penetration is restricted by the cutting ring's design. At the same time, the ring has become wedged between pipe and union. This achieves a positive lock in both radial and axial direction. Thanks to the shape and high degree of positive locking any forces that arise get efficiently spread across the whole cone length. This achieves optimum resistance to vibration and a high level of reliability against flexural fatigue stress or fluctuations in pressure or temperature. By virtue of the high surface quality it is possible to achieve relatively advantageous levels of tightening torque. The noticeable increase in torque (after the cutting edges take grip as intended) makes it easy to spot any risk of 'over tightening'. Slight 'over tightening' does not impair the overall function.

Before tightening the union nut After tightening the union nut

Vor dem Anzug der Überwurfmutter
Nach dem Anzug der Überwurfmutter

2.1.2 Determining the pipe diameter

DIN 1988-3 is applicable for dimensioning. Accordingly the figures from table 19 of this standard are to be taken as the basis for the pressure loss due to pipe friction and those from table 27 as the basis for individual resistances. It is essential - as already explained at 2.1.1 - to avoid any over-dimensioning. Additionally applicable for drinking water circulation pipelines is DVGW worksheet W 553 'Design of circulation systems in central drinking water heating facilities'.

2.1.3 Thermal insulation

In order to keep heat loss as low as possible the following sets of rules need to be adhered to for hot pipes, pipes for heated drinking water and drinking water circulation pipes:

• DIN 4108, Thermal protection in buildings,

• Energy-Saving Directive (EnEV),

• Thermal Protection Directive (WschutzV).

The minimum levels of insulation thickness pursuant to these are contained in table 6.

Pipes for cold drinking water must be protected against impermissible heating up of the water and, where applicable, against the formation of condensate. They must be laid at a sufficient distance from sources of heat (e.g. hot pipes, chimney stacks or heating systems). If this is not possible, the pipes must be insulated such that the water quality is not impaired by heating up. Under usual operating conditions in the construction of flats thermal insulation needs to be provided. The thickness of the insulation can likewise be derived from table 6.

In selecting the insulating material attention should be paid to using material that is practically free of any chlorides. The per cent by weight of water-soluble chloride ions in the insulating material must not exceed 0.05%.

 

2.1.4 Noise protection

In order to ensure noise protection as defined by DIN 4109, it can be necessary in a few cases to wrap the pipe in elastic material. Here too the requirements in relation to the material being free of chlorides - as described above for thermal insulation material - must be observed. For pipe fixing suitable clamps with rubber inlays must be used (SANHA® catalogue no. 9918). For fixing distances see 2.2.13.

Pipeline for cold drinking water

 

Pipeline for heated drinking

Installation situation

Insulation thickness in mm  in mm

λ = 0,040 W m-1 K-1

Outer Ø in mm

Outer Ø in mm
λ = 0,035 W m-1 K-1

Pipeline laid exposed, in non-heated room (e.g. cellar)

4

15,0

20

Pipeline laid exposed, in heated room

4

15,0

20

Pipeline in duct, without any hot pipes Rohrleitungen

4

22,0

20

Pipeline in duct, next to hot pipes

13

28,0

30

Pipeline in masonry slot, riser

4

35,0

30

Pipeline in wall cavity,
next to hot pipes

13

42,0

40

Pipeline on concrete ceiling

4

54,0

50

 

-

76,1

65

 

-

88,9

80

 

-

108,0

100

2.2 Laying instructions

2.2.1 Storage and transportation

During transportation and storage care must be taken to prevent the products becoming damaged or dirty or coming into contact with any iron or non-alloyed steel. When transporting by lorry, for example, it is therefore advisable to cover the cargo bed with a film if the lorry has previously carried pipes or components made of non-alloyed steel.

2.2.2 External corrosion protection

Stainless steel's high resistance to corrosion generally makes any external form of corrosion protection unnecessary. In special situations, such as in atmospheres containing chloride or chlorine (e.g. in swimming baths) even the stainless steel pipes of the SANHA® NiroSan® press-fit system do need protecting. Particularly suitable for doing this are chloride-free corrosion protection bands as per DIN 30672, which vulcanise in the overlap area into a homogeneous sheath coating. When adding these, attention must be paid to ensuring that there are no gaps in the sheathing. The corrosion protection bands must overlap by at least 15 mm.

2.2.3 Mixed installation

A mixed installation of the SANHA® NiroSan® press-fit system with other materials used in the drinking water installation does not have any detrimental effect on the corrosion characteristics of the SANHA® NiroSan® press-fit system. No particular sequencing of materials (as in the flow rule familiar in connection with copper and zinc-plated steel) needs to be taken in account. 


In the event of contact with zinc-plated steel the latter becomes anodically polarised, which can lead to it being damaged by contact corrosion. Experience shows that a sufficient reduction in the likelihood of such damage can be achieved by creating a gap of around one pipe diameter between non-corroding steel and zinc-plated steel. This can be most easily achieved, for example, using a fitting between the two steels made of gunmetal or brass.

A mixed installation of the SANHA® NiroSan® press-fit system using components made of copper and/or copper alloys presents practically no problems at all. Only with very unfavourable surface ratios (percentage of the surface of all components made of copper materials in the whole installation appreciably less than 2%) is it possible in further unfavourable conditions for damage caused by contact corrosion to occur to a component made of copper materials.

2.2.4 Seals and sealing aids

Seals, such as flat gaskets, must not give off any chloride ions into the water or lead to any local concentrations of such ions. The seals used for SANHA® components, i.e. Centellen® seals (SANHA® catalogue no. DCU) fulfil this requirement. For threaded connections we recommend using a permanently elastic thread seal. When using hemp, a chloride-free sealing aid must be used. Using thread sealing tape (Teflon tape) is not recommended.

2.2.5 Bending

Hot bending stainless steel pipes is not allowed. The SANHA® NiroSan® system pipes of dimensions 15 mm to 28 mm can be cold bent using suitable bending tools. You must keep here to a bend radius (measured in the elbow's neutral axis) of at least r = 3.5 x da, where da is the outer diameter of the pipe.

2.2.6 Cutting

SANHA® NiroSan® system pipes should preferably be cut using a fine-toothed metal saw – ensuring that the saw blade has definitely not been previously used to cut any non-alloyed steel – or a pipe cutter (SANHA® catalogue no. 4985, specially for stainless steel). If an electrically powered saw is used, then in order to avoid making the material susceptible the cutting speed must not be so fast that any discolouring occurs around the cut. One suitable saw, for example, is the +GF+ RA 21 planetary saw.. Using cutting disks (Flex), not to mention cutting torches, is not allowed.

Caution!

After being cut to length, the pipe ends must be carefully deburred inside and outside (for pipes up to 54 mm outer diameter: SANHA® catalogue no. 4985).

 

2.2.7 Testing for leaks

Testing to ensure there are no leaks can be done either with water as per DIN 1988-2 or on a dry basis using an inert gas or oil-free compressed air as per the ZVSHK leaflet 'Testing for leaks with air' or BHKS rule 5.001 'Pressure testing of drinking water pipes using compressed air or nitrogen'. This must be done at a time when the joint locations are still accessible and have not been covered over. Dry testing for leaks is always advisable if it is going to be a relatively long time between the pressure test and actually starting to operate the installation. This is always the case whenever proceeding step by step on major building projects. If, as is customary on smaller building projects, the complete installation is being tested, the pressure trial can be done using water. In this case, the pipelines should be left sealed off and completely emptied or - as with the usual running of pipes these days that is hardly ever possible - completely filled with water up until they start to be used / until the flushing process to be carried out immediately prior to that. If there is a risk of frost during this period, then dry leak testing is to be favoured.

2.2.8 Flushing the drinking water installation

As a general principle, all drinking water pipelines, regardless of the type of material used, must be thoroughly flushed using filtrated drinking water. Flushing must be done as early as possible and after the pressure testing.

It should achieve the following objectives:

• Flushing of the drinking water quality (hygiene),

• Cleaning of the pipe inner surfaces,

• Avoidance of faults on fittings and devices

These requirements are met by two flushing methods. These are:

• Flushing with an air-and-water mix as per DIN 1988-2. Section 11.2,

• Flushing with water as per ZVSHK leaflet called 'Information on flushing drinking water installations designed in accordance with TRWI DIN 1988.'

For drinking water installations that have been created using the SANHA® NiroSan® press-fit system either flushing method can be used. Using either method the hygienic requirements that are made of drinking water installations will be fulfilled. Additional disinfection of the pipeline system is not called for in DIN 1988-2 and is also generally not necessary. If as an exception to the rule in an individual case disinfection of the pipelines is nevertheless necessary for any particular reason, details should be agreed in advance with our technical customer support team. Chlorine dioxide must not under any circumstances be used as the disinfectant.

Pressure testing, flushing and handover

where building progress is fast

Variant 1 (wet)

Where there are long intervals between pressure testing and starting operation, Variant 2 (dry)

 

  1. Fit fine filter

  2. Fill the pipelines for the first time with filtrated drinking water and fully bleed.

  3. Perform pressure trial
  4. Flush the installation using filtrated drinking water as per DIN 1988-2 or ZVSHK leaflet called 'Information on flushing drinking water installations designed in accordance with TRWI DIN 1988.'

  5. Bleed pipelines and leave filled and under pressure
    (avoid emptying / partial emptying)

  6. Operational handover of the system. Give client initial instruction and draw attention to DIN 1988-8
    (avoiding any relatively long downtimes, necessary maintenance jobs)

 

 

  1. Test pipeline for leaks using inert gas (e.g. oil-free compressed air, nitrogen) at 3 bar, including a section at a time, depending on building progress

  2. Fit fine filter

  3. Fill the pipelines for the first time with filtrated drinking water just before intended operational handover of the installation











 

2.2.9 Electric trace heating

Electric trace heating can be used for the SANHA® NiroSan® press-fit system if the pipe inner wall temperature never exceeds 60°C. Briefly exceeding this level and going up to 70°C for the purposes of thermal disinfection (see DVGW worksheet W 552) is permissible.

When using electric trace heating, any sealed off pipeline sections that do not have their own safety mechanisms may not be heated. This is in order to avoid any impermissible increase in pressure in such sections. DIN 1988-4 / DIN EN 1717 must be observed without fail.

2.2.10 Electrical protective measures

In accordance with DIN VDE 0100, potential equalisation must be run for all electrically conductive pipelines. The SANHA® NiroSan® press-fit system is a pipe connection capable of conducting electric current from end to end and must thus be included in the potential equalisation. The person or company installing the electrical systems is responsible for carrying out these electrical protective measures.

2.2.11 Lengthways expansion and fixing of the pipelines

Depending on the temperature difference hot pipes expand to varying degrees (see picture 6). If the pipelines are hindered in this thermally induced lengthways change, then the mechanical tension levels prevailing within the pipeline material may exceed the permitted level, as a result of which damage (generally in the form of fatigue cracks) can occur. In order to avoid this, the pipeline must be given sufficient room to expand.

The thermal expansion coefficient of stainless steel material no. 1.4401 is of the same order as that of copper. Table 8 shows the expansion coefficients of several pipe materials. In table 9 you can see the change in length dependent on temperature difference and length of pipe.

Example:

For a pipeline for heated drinking water of 8 metres in length with an operating temperature of tW = 60°C and a cold water temperature of tK = 10°C you need to work out the change in length ¢ l as a result of thermal expansion.

Temperature difference ∆ t = tW – tK = 60°C – 10°C = 50 K

From table 9 we can see in the column for 50 K and the
row for 8 m the change in length of the SANHA® NiroSan® system pipe of ∆l = 6.6 mm that needs to be taken into account.

The elasticity of the pipe network can often be used to compensate for these changes in length. To this end it is necessary in the area of pipeline bends to create sufficiently flexible pipeline sides through correct arrangements of the securing clamps (see picture 7 and table 10).

The basic principle is that between any two fixed points there must always be an adequate possibility of expansion.

If the natural run of the pipes does not facilitate sufficient compensation of the thermal expansion, this has to be achieved through the fitting of special components, such as, for example, metal bellow expansion joints. If there is sufficient space available, it is also possible to use a U-pipe expansion joint as per picture 8 / table 11.

Pipe material

Coefficient of thermal expansion

∆ l in mm for Lo = 10 m

 

α in 10-6 K-1 (20 bis 100 ⁰C)

∆ T = 50 K

Stainless steel

16,5

8,3

Copper

16,6

8,3

Steel pipe, zinc-plated

12,0

6,0

Plastic (depending on pipe material)

80 to 180

40 to 90

 

 

 

Required side length X in m

Pipe outer Ø

Expansion absorption in mm

in mm

5

10

15

20

25

30

35

15,0

0,40

0,57

0,69

0,80

0,90

0,98

1,06

18,0

0,44

0,62

0,76

0,88

0,98

1,08

1,16

22,0

0,49

0,69

0,84

0,97

1,09

1,19

1,28

28,0

0,55

0,77

0,95

1,10

1,22

1,34

1,45

35,0

0,61

0,87

1,06

1,22

1,37

1,50

1,62

42,0

0,67

0,95

1,16

1,34

1,50

1,64

1,77

54,0

0,76

1,08

1,32

1,52

1,70

1,86

2,01

76,1

0,90

1,28

1,56

1,81

2,02

2,21

2,39

88,9

0,98

1,38

1,69

1,95

2,18

2,39

2,58

108,0

1,08

1,52

1,86

2,15

2,41

2,63

2,85

 

 

 

 

 

 

 

 

 

in mm

40

45

50

55

60

65

70

75

15,0

1,13

1,20

1,27

1,33

1,39

1,45

1,50

1,55

18,0

1,32

1,39

1,46

1,52

1,58

1,64

1,70

22,0

1,46

1,54

1,61

1,68

1,75

1,82

1,88

28,0

1,64

1,73

1,82

1,90

1,97

2,05

2,12

35,0

1,84

1,94

2,03

2,12

2,21

2,29

2,37

42,0

2,01

2,12

2,22

2,32

2,42

2,51

2,60

54,0

2,28

2,41

2,52

2,63

2,74

2,85

2,95

76,1

2,71

2,86

2,99

3,13

3,26

3,38

3,50

88,9

2,93

3,09

3,24

3,38

3,52

3,65

3,78

108,0

3,23

3,40

3,57

3,73

3,88

4,02

4,17

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 Length of the U-elbow L in mm

Pipe outer Ø

Expansion absorption in mm

in mm

5

10

15

20

25

30

35

40

15,0

0,23

0,33

0,40

0,46

0,52

0,57

0,61

0,65

18,0

0,25

0,36

0,44

0,51

0,57

0,62

0,67

0,72

22,0

0,28

0,40

0,49

0,56

0,63

0,69

0,74

0,79

28,0

0,32

0,45

0,55

0,63

0,71

0,77

0,84

0,89

35,0

0,35

0,50

0,61

0,71

0,79

0,87

0,94

1,00

42,0

0,39

0,55

0,67

0,77

0,87

0,95

1,02

1,10

54,0

0,44

0,62

0,76

0,88

0,98

1,08

1,16

1,24

76,1

0,52

0,74

0,90

1,04

1,17

1,28

1,38

1,47

88,9

0,56

0,80

0,98

1,13

1,26

1,38

1,49

1,59

108,0

0,62

0,88

1,08

1,24

1,39

1,52

1,64

1,76

 

 

 

 

 

 

 

 

 

in mm

45

50

55

60

70

80

90

15,0

0,69

0,73

0,77

0,80

0,87

0,93

0,98

18,0

0,76

0,80

0,84

0,88

0,95

1,01

1,08

22,0

0,84

0,89

0,93

0,97

1,05

1,12

1,19

28,0

0,95

1,00

1,05

1,10

1,18

1,26

1,34

35,0

1,06

1,12

1,17

1,22

1,32

1,41

1,50

42,0

1,16

1,22

1,28

1,34

1,45

1,55

1,64

54,0

1,32

1,39

1,46

1,52

1,64

1,76

1,86

76,1

1,56

1,65

1,73

1,81

1,95

2,09

2,21

88,9

1,69

1,78

1,87

1,95

2,11

2,25

2,39

108,0

1,86

1,96

2,06

2,15

2,32

2,48

2,63

 

 

 

 

 

 

 

 

 

Where pipes are laid concealed unimpaired thermal expansion must be ensured by the pipes being clad in elastic chloride-free material of sufficient thickness.

Pipe runs through ceilings, in particular, must - unless a fixed point has been consciously positioned there - be carefully padded out (see pictures 9-11).

 

2.2.12 Space requirements

The distance of the pipeline from walls, in corners and wall slots that is required for assembly is shown by the following sketches and tables.

Pipe outer Ø

Nominal width

Insertion depth

Minimum distance


mm


DN


mm

Amin
mm

Imin
mm

Bmin
mm

Cmin
mm

15,0

12

25

10

60

60

85

18,0

15

25

10

60

60

85

22,0

20

28

10

66

60

88

28,0

25

29

10

68

60

89

35,0

32

30

10

70

60

90

42,0

40

38

20

96

60

98

54,0

50

44

20

108

60

104

76,1

65

50

30

130

60

110

88,9

80

57

30

144

60

117

108,0

100

69

30

168

60

129

 

 

 

 

 

 

 

 

Pipelines concealed below plaster
Pipelines in ceiling openings
Pipelines beneath the screed (within thermal and footfall sound insulation)
Minimum gap between two crimp points
Minimum gap between wall and crimp point
Minimum gap A of the pipelines
to the wall and minimum gap C of the pipelines from each other
Minimum gap A of the pipelines

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