Admiral Valve Repair And Supply

ASME Section I

This code applies to boilers where steam or other vapor is generated at a pressure greater than 15 psig and high temperature water boilers intended for operation at pressures exceeding 160 psig and/or temperatures exceeding 250 deg F. 

SINGLE VALVE INSTALLATION:

Boilers less than 500 sq. ft. of heat surface and generates less than 4000 #/hr. (PG-67.1) 

Must be set at or below the design pressure of the vessel.

MULTIPLE VALVE INSTALLATION:

When only 2 valves are used, the capacity of the smaller valve shall not be less that 50% of the larger valve.  (PG-71.1) 

The complement of the spring loaded valves must be able to relieve 100% of the boiler steaming capacity.  (PG-67.2) 

Any additional valves can not be set in excess of 3% above then design pressure.  The set pressure range for saturated steam valves shall not exceed 10% of the highest valve’s set pressure. 

SUPERHEATER:

There shall be at least one valve installed on the superheater  outlet. 

The superheater valve capacity may be included in the complement of valve capacities provided the aggregate capacity of the drum valves is at least 75% of the boiler steaming capacity.  (PG-68.1 & PG-68.2) 

REHEATER:

There shall be at least one or more valves to relieve the maximum reheater steam flow.  There shall be at least one valve on the reheater outlet such that the relieving capacity shall not be less than 15% of the required total. 

Credit for reheater valves cannot be taken in determining the required capacity for drum and superheater valves.  (PG-68.4) 

SET PRESSURE TOLERANCES:

For pressures above 15 psig up to and including 70 psig, the tolerance shall be +/- 2 psig.

For pressures above 70 psig up to and including 300 psig, the tolerance shall be +/- 3%.

For pressures above 300 psig up to and including 1000 psig, the tolerance shall be +/- 10 psig.

For pressures above 1000 psig, the tolerance shall be +/- 1%.  

ASME Boiler and Pressure Vessel Code Section I (2001)