ANSI AWWA C905-10 pdf free download – Polyvinyl Chloride (PVC) Pressure Pipe and Fabricated Fittings, 14 In.
18. Recurring (cyclic) surge pressure (P RS ): Surge pressures that occur fre- quently and are inherent to the design and operation of the system (such as normal pump startup or shutdown and normal valve opening or closure). Recurring surge pressures may occur up to millions of times in a piping system’s lifetime.
19. Standard dimension ratio (SDR): A dimension ratio that corresponds to one of the numbers in the standard series of preferred dimension ratios that has been established by ASTM International (ASTM F412).
20. Supplier: T e party that supplies material or services. A supplier may or may not be the manufacturer.
21. Surge pressure (P s ): The maximum hydraulic transient pressure increase (sometimes called water hammer) in excess of the operating pressure that is antici- pated in the system as the result of sudden changes in velocity of the water column. For purposes of product selection and design, this document considers the follow- ing two types of surges: a. Recurring (cyclic) surge pressure (P RS ). b. Occasional (emergency or transient) surge pressure (P OS ). Note: Occasional transients caused by emergency pump and valve opera- tions are usually severe. The system should be designed to withstand positive and negative pressures caused by these emergency operations. Water column separation may occur if the negative pressure is reduced to the vapor pressure of the liquid. Rejoining of the separated water column typically results in a large pressure rise, which will possibly damage the pipe system. Whenever possible, water column separation should be avoided.
T e selection of materials is critical for water service and distribution piping in locations where there is likelihood the pipe will be exposed to signifi cant con- centrations of pollutants comprised of low-molecular-weight petroleum products or organic solvents or their vapors. Research has documented that pipe materials such as polyethylene, polybutylene, PVC, and asbestos cement; and elastomers, such as used in jointing gaskets and packing glands, are subject to permeation by lower-molecular-weight organic solvents or petroleum products. If a water pipe must pass through such a contaminated area or an area subject to contamination, consult with the manufacturer regarding permeation of pipe walls, jointing materi- als, etc., before selecting materials for use in that area.
4.2.3 Rework materials. Clean rework materials derived from a manufac- turer’s own pipe or fi tting product may be used by the same manufacturer for similar purposes provided that (1) the cell classifi cation of the rework material is identical to the material to which it will be added; (2) the rework material complies with applicable requirements of Sec. 4.2 of this standard; and (3) the fi nished prod- ucts comply with the requirements of this standard.
4.2.4 Certifi cation for potable-water service. PVC compounds and prod- ucts shall be tested for chemical extractants and certifi ed as suitable for potable water service by an accredited testing agency acceptable to the purchaser. T e basis of certifi cation shall be the requirements specifi ed in NSF/ANSI 61.
4.2.5 Gaskets and lubricants. Gaskets and lubricants intended for use with PVC pipe and fabricated fi ttings shall be made from materials that are compatible with the pipe and with each other when used together. Gaskets and lubricants shall not adversely aff ect the potable quality of the water that is to be transported (see foreword, Sec. I.C).
4.2.5.1 Elastomeric gaskets. One gasket shall be furnished with each bell end of every pipe, fi tting, and coupling. Elastomeric gaskets shall meet the require- ments of ASTM F477 for high-head (50 ft of head or higher) applications.
4.2.6 Fabricated fi tting overwrap reinforcement. Optional reinforcement, either PVC or non-PVC, may be applied by the manufacturer to meet the require- ments of this standard.
4.2.6.1 Resin. Resin used shall be a commercial grade of unsaturated polyester resin or epoxy resin.
4.2.6.2 Glass. Glass reinforcing materials shall be commercial “E” type glass in the form of mat, continuous roving or roving fabric, or a combination of these, having a coupling agent that bonds the glass reinforcement and the resin.