DWV Pipe Under Pressure?
DWV Pipe Under Pressure?
(OP)
I have a 2 filters that were installed using 1.5" DWV pipe. I can't seem to find any specs or pressure ratings on DWV pipe. Although the pipe does have 1.5" SCH 40 PVC........DWV. In another place the pipe is labeled PSI 330 @ 73 degrees. Why would DWV pipe be rated for 330 psi? This is really throwing me. It seems the pipe is ok for pressure situations (as it's already installed), but I'd like to make sure it's alright over the long run.
Any thoughts?
Thanks
Any thoughts?
Thanks





RE: DWV Pipe Under Pressure?
RE: DWV Pipe Under Pressure?
The 330 psi is probably not really the pipe pressure rating. The 330 psi is probably the quick burst pressure rating.
This was discussed in another thread:
thread164-155889: PVC 40 vs JIS K 6741
http://www
Pressure class or pressure rating of the PVC product refers to anticipated steady-state continuous operating capability and are based on long term material strength. Desing for long term, steady state operating conditions based on short term strength of PVC pipe would be inappropriate. The Pressure class or pressure rating takes into account the long term response of PVC pipe to applied stress.
The quick-burst pressure or short-term strength divided by a safety factor of 2.5 will yield the corresponding short-term pressure rating of the pipe. The short-term pressure rating should be considered the design surge capacity limit for PVC in a transmission application. The short-term pressure rating represents a level approximately 25%a above the pressure rating for each rating class.
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RE: DWV Pipe Under Pressure?
complete pipe details as shown on pipe:
1 1/2" SCH 40 PSI 330 @ 73 PVC 1120 ASTM D 1785 (CO. LOGO) ASTM D 2665 (CO. LOGO)S.P.C. (can't make out the rest)
I can't make out the manufacturer or I'd just call them. Could it be that the pipe is dual purpose?
RE: DWV Pipe Under Pressure?
RE: DWV Pipe Under Pressure?
It is common for plumbers to use PVC 40 pipe for DWV applications. Many manufacturer's make "dual mark" pipe for both pressure and DWV applications. They also make "foam core" which has internal fillers and foam, hence reducing the amount of virgin resin required (and the cost) and only rated for DWV applications. Home Depot typically has this pipe in stock. But it is clearly labeled as such.
Check your fittings, they are really the determining factor
RE: DWV Pipe Under Pressure?
http:/
The pressure ratings of thermoplastic pipe represent the maximum allowable operating pressure within a piping system for water at 72°F (23.4°C) based upon a service factor of 0.5.
Plastic piping systems must be derated for surge pressures in addition to a temperature derating. It is best to consider the actual surge conditions that the piping will be exposed to. In addition, substantial reductions in working pressure are advisable when handling aggressive chemical solutions.
One would suspect that the water treatment supplier is using a high velocity (higher than 5 ft/sec) in the filter piping to save cost. That high velocity combined with the cycling of valves will lead to a substantial derating of the pipe pressure rating.