The pipe leaving the relief valve should be the same diameter as the exhaust port of the valve — usually
3/4 inch
. Moreover, the pipe should be made of a material that is not adversely affected by heat, such as copper.
How do you size a relief valve?
The valve size
must correspond to the size of the inlet and discharge piping
. The National Board specifies that the both the inlet piping and the discharge piping connected to the valve must be at least as large as the inlet/discharge opening on the valve itself.
What is code for water heater pressure relief valve?
Item 10
requires the relief valve to terminate no more than 6 inches (152mm) above the floor surface, a waste receptor or floor drain in order to prevent hot water discharge from being directed onto a building occupant that may be nearby.
Can you use PVC for pressure relief valve?
Can you use PVC pipe for the water heater temperature pressure relief (TPR) discharge pipe? No.
PVC pipe is not rated by the building code for use with hot water
, so the installation shown above is wrong and unsafe. … Pipe materials that are rated for hot water include CPVC, copper, galvanized, and PEX.
Can you use PEX for water heater relief valve?
Can you use PEX as discharge pipe at water heater temperature and pressure relief (TPR) valve?
Yes
. PEX (cross-linked-polyethylene) is rated for water distribution by the International Residenital Code (IRC) at Table P2906. … 6.1(13) that any rated pipe is acceptable for TPR discharge.
What is maximum allowable relief valve setting?
The set point of the relief device should be set at or below this point. When the pressure relief valve to be used has a set pressure below 30 psig, the ASME Code specifies a maximum allowable overpressure of
3 psi
. … Variable built- up back pressure should not be permitted to exceed 10% of the valve set pressure.
How do you size a temperature and pressure relief valve?
The only way to determine the maximum allowable working pressure of a vessel is to read the nameplate that is attached to it. The pressure on the valve’s tag must be compared to the pressure on the vessel’s nameplate. The pressure rating of the relief valve must be
equal
to or less than the MAWP of the vessel.
Does pressure relief valve need pipe?
The Temperature & Pressure Relief Valve or TPR Valve on any heated appliance that contains water, such as a heating boiler, hot water tank, water heater, water cylinder, must have
a drain line or discharge tube properly installed
, routed, and made of proper materials.
Why is my hot water heater leaking from the pressure relief valve?
Your water heater’s relief valve can start leaking for one of two reasons: either
the valve was triggered to open because of excessive temperature or pressure
, or the valve itself is faulty. … If the problem is a faulty valve, then you might have an actual leak.
Can you terminate the TPR temperature pressure relief valve discharge pipe to the water heater pan?
Per the 2015 Uniform Plumbing Code can you terminate the TPR(Temperature Pressure Relief Valve) discharge pipe to the water heater pan? receiving the discharge and pointing down. … (6) The terminal end of the pipe shall not be threaded. (7)
Discharge from a relief valve into a water heater pan shall be prohibited
.
What kind of PVC do you use for hot water?
CPVC (schedule 80) pipe
is rated for use up to 200 degrees Fahrenheit. This makes it ideal for use on hot water lines in homes and businesses.
Can PVC be used for hot water lines?
By far the most commonly used pipe in residential homes, polyvinyl chloride (PVC) pipe is the white piping commonly used in plumbing applications. … When exposed to hot water, PVC will warp. This means
it cannot be used to deliver hot water to sinks, tubs and washing machines
.
Can CPVC be used for hot and cold water?
Applications of PVC & CPVC:
PVC is still often used for unheated water as well as for vent and drainage systems; however,
CPVC has become widely used for both hot and cold potable water
. The more resistant properties of CPVC make it useful for commercial and industrial applications as well.
Can you use PEX for drain line?
Since it first gained favor near the dawn of the millennium, PEX has emerged as an industry standard in water-supply line piping due to its strength and heat tolerance. … PEX’s purpose, however, is the opposite of PVC — whereas the latter is restricted to drain lines, the former is
only used for incoming water lines
.
Can I use PEX for condensate line?
You could use
PEX tubing or Vinyl
, but you need to make sure that it does not get kinked in any way and that it has a large enough ID to accomadate the flow of water or you will be asking for trouble. Also make sure that you are allowed to tie into the main drain line.
What temperature is CPVC rated for?
CPVC’s superior temperature resistance is exhibited in the ASTM standards for each material, as the maximum service temperature for PVC is up to 140°F (60°C) and for CPVC it is
up to 200°F (93.3°C)
.
