- SDR 9 CTS PEX tubing complying with ASTM F876 and pressure-rated in accordance with PPI TR-3; and
- PEX fitting systems complying with
- ASTM F877, for mechanical compression fittings and metal or plastic insert fittings with stainless steel press sleeves;
- ASTM F1807 or ASTM F2159, for metal or plastic insert fittings with copper crimp rings;
- ASTM F1960, for cold expansion fittings with PEX reinforced rings; or
- ASTM F2080, for cold expansion fittings with metal compression sleeves.
- "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy to comply with the Standard;
- "should" is used to express a recommendation, but not a requirement;
- "may" is used to express an option or something permissible within the scope of the Standard; and
- "can" is used to express a possibility or a capability.
This Standard refers to the following publications, and where such reference is made, it shall be to the current edition of those publications, including all amendments published thereto.
|ASTM F876||Standard Specification for Crosslinked Polyethylene (PEX) Tubing|
|ASTM F877||Standard Specification for Crosslinked Polyethylene (PEX) Hot- and Cold-Water Distribution Systems|
|ASTM F1807||Standard Specification for Metal Insert Fittings Utilizing a Copper Crimp Ring for SDR9 Cross-linked Polyethylene (PEX) Tubing and SDR9 Polyethylene of Raised Temperature (PE-RT) Tubing|
|ASTM F1960||Standard Specification for Cold Expansion Fittings with PEX Reinforcing Rings for Use with Cross-linked Polyethylene (PEX) Tubing|
|ASTM F2080||Standard Specification for Cold-Expansion Fittings With Metal Compression-Sleeves for Cross-Linked Polyethylene (PEX) Pipe|
|ASTM F2159||Standard Specification for Plastic Insert Fittings Utilizing a Copper Crimp Ring for SDR9 Cross-linked Polyethylene (PEX) Tubing and SDR9 Polyethylene of Raised Temperature (PE-RT) Tubing|
|ASTM F2657||Standard Test Method for Outdoor Weathering Exposure of Crosslinked Polyethylene (PEX) Tubing|
|AWWA C904||Cross-Linked Polyethylene (PEX) Pressure Tubing, 1/2 In. (12 mm) Through 3 In. (76 mm) for Water Service|
|IAPMO/ANSI UPC-1||Uniform Plumbing Code|
|PPI TR-3||Policies and Procedures for Developing Hydrostatic Design Basis (HDB), Pressure Design Basis (PDB), Strength Design Basis (SDB), and Minimum Required Strength (MRS) Ratings for Thermoplastic Tubing Materials or Tubing|
- pigmented throughout (i.e., with color);
- non-pigmented (e.g., translucent or natural); or
- coated with a pigmented layer.
- are made of brass, stainless steel, or sulfone;
- consist of an insert and a PEX reinforcing ring; and
- are available in NTS-3/8 to NTS-3.
- are made of brass, stainless steel, or sulfone;
- consist of an insert and a copper crimp ring or a stainless steel press ring
- are available in NTS-3/8 to NTS-2.
- are made of brass; and
- consist of
- a nut, a compression ring, and an insert; or
- an O-ring brass insert with a compression sleeve
- are available in NTS-1/4 to NTS-3.
- At the time of unloading, the markings of all tubing, fittings, and accessories shall be verified to ensure that all items have been manufactured in accordance with the applicable product Standard and appropriately certified.
- An overall examination of the shipment shall be made. If the shipment is intact, ordinary inspection while unloading shall be sufficient to ensure that the items have arrived in good condition.
- If the load has shifted, has broken packaging, or shows evidence of rough treatment, each item shall be carefully inspected for damage.
- The total quantities of each shipment (e.g., tubing, gaskets, fittings, and accessories) shall be checked against shipping records.
- Any damaged or missing items shall be noted on the delivery slip. The carrier shall be notified immediately and a claim made in accordance with its instructions.
- No damaged material shall be disposed of. The carrier shall recommend the procedure to follow.
- Shortages and damaged materials are normally not reshipped without request. If replacement material is needed, it shall be reordered from the manufacturer, the distributor, or a manufacturer's representative.
Note: ASTM F876 has four categories for UV-resistance, ranging from untested to 6 months of continuous exposure, as listed in the material designation code.
- arms with rigid anchor points; and
- supporting the tubing with continuous runs of CTS support channels with
- rigid anchor points installed every 20 m (65 ft); and
- proper strapping (e.g., 27 kg (60 lb) straps or equivalent) spaced 1 m (3 ft) and rated for the maximum temperature and UV exposure of the PEX tubing application.
- a riser clamp at the top of every other floor; and
- mid-story guides to maintain the alignment of the vertical tubing.
LB = C × √(D × ΔL)
|LB||=||length of flexible arm|
|C||=||material constant (12 for PEX)|
|D||=||nominal outside diameter of tubing|
|ΔL||=||thermal expansion length|
- be supported at each floor or as specified by the water-distribution system designer to allow for expansion and contraction; and
- have mid-story guides.
- NTS-1 and smaller shall be supported every 0.8 m (32 in), unless continuously supported by metallic CTS or V channels that
- are supported at intervals not exceeding 1.8 m (6 ft);
- have a maximum cantilever, measured from the support to the end of the CTS support channel, of 0.5 m (1.5 ft); and
- NTS-11/4 and larger shall be supported every 1.2 m (4 ft), unless continuously supported by metallic CTS or V channels that
- are supported at intervals not exceeding 2.4 m (8 ft); and
- have a maximum cantilever, measured from the support to the end of the CTS support channel, of 0.5 m (1.5 ft).
- used to restrict PEX tubing movement;
- made of materials that provide rigidity to the support system and utilize pipe clamps designed for plastic tubing capable of restraining the tubing; and
- installed in accordance with Figures 1 or 2, as applicable (i.e., anchor distances and size of arms and offsets).
- made at least 500 mm (18 in) from PEX tubing in the same water line; and
- performed prior to completing the PEX joints.
Directional fittings (e.g., 90° and 45° elbows) should only be installed where necessary.
Note: The flexible nature of PEX tubing allows for sweeping bends resulting in less fittings and joints.
Note: AWWA C904 should be consulted for water service applications.
- 3.0 m/s (10 ft/s) for cold-water distribution systems; and
- 2.4 m/s (8 ft/s) for hot-water distribution systems.
|NOMINAL TUBING SIZE||FLOW VELOCITY: 3.0 m/s (10 ft/s)||FLOW VELOCITY: 2.4 m/s (8 ft/s)|
|FLOW VOLUME, L/min (gpm)||FLUSH TANK FIXTURE UNITS||FLUSH VALVE FIXTURE UNITS||FLOW, L/min (gpm)||FLUSH TANK FIXTURE UNITS||FLUSH VALVE FIXTURE UNITS|
|1/2||20.8 (5.5)||6||—||16.7 (4.4)||4||—|
|11/4||103.0 (27.2)||46||10||82.5 (21.8)||33||5|
|11/2||143.5 (37.9)||77||24||114.7 (30.3)||54||13|
|2||246.1 (65.0)||200||91||196.8 (52.0)||135||52|
|3||533.0 (140.8)||590||495||426.2 (112.6)||443||310|
- be balanced to maintain adequate system temperatures; and
- have flow velocities that do not exceed 0.6 m/s (2 ft/s) (see Table 2); and
- use only PEX tubing designated for hot, chlorinated water recirculation systems and rated for the maximum percentage of time during which the system is intended to be operated at elevated temperatures, in accordance with ASTM F876.
|NOMINAL TUBING SIZE||FLOW VELOCITY
|FRICTION LOSSES AT 49 °C (120°F)
|1/2||0.6 (2)||4.2(1.1)||0.4411 (0.0195)|
|3/4||0.6 (2)||8.3 (2.2)||0.2850 (0.0126)|
|1||0.6 (2)||13.6 (3.6)||0.2081 (0.0092)|
|11/4||0.6 (2)||20.4 (5.4)||0.1629 (0.0072)|
|11/2||0.6 (2)||28.4 (7.5)||0.1335 (0.0059)|
|2||0.6 (2)||48.8 (12.9)||0.0950 (0.0042)|