Admiral Valve Repair And Supply

ASME Section IV

 

This code applies to steam boilers operating at pressures not greater than 15 psig and hot water heating boilers operating at pressures not greater than 160 psig and/or temperatures not greater than 205 deg F.

 

STEAM BOILERS:

Valve capacity must be selected to prevent the boiler pressure from rising more than 5 psig above the MAWP.

 

STEAM TO HOT WATER SUPPLY:

 

Valve must be at least 1-inch diameter with set pressure not greater than MAWP of the tank.

 

HOT WATER BOILERS:

 

Safety valve must be set to relieve at a pressure not greater than the MAWP of  the boiler. If more than one safety valve is used, the secondary valve(s) may be set up to 6 psig above the MAWP for boilers with MAWPs up to and including 60 psig, and 5% for boilers with MAWPs greater than 60 psig. Capacity must be selected to prevent the pressure from rising more than 10% above the MAWP if one valve is used or 10% above the set pressure of the highest set valve if more than one valve is used.

 

TANKS/HEAT EXCHANGERS:

High Temperature Water-to-Water Heat Exchanger

Valve(s) must be set a pressure not greater than the MAWP and with sufficient capacity to prevent the pressure from increasing more than 10% above the MAWP.  

High Temperature Water to Steam Heat Exchanger

Valve must be set at a pressure not greater than 15 psig and with sufficient capacity to prevent the pressure from rising more than 5 psig above the MAWP. 

 

SET PRESSURE TOLERANCES:

Steam: For pressures of 15 psig, the tolerance shall be +/- 2 psig.

Hot Water: For pressures of 15 psig up to and including 60 psig, the tolerance shall be +/- 3 psig.

                     For pressures of 61 psig up to and including 160 psig, the tolerance shall be +/- 5%.