Selecting the Proper Valve...
Aquatrols valves are factory set,
tested, sealed and tagged to service your specific application.
Air, Steam, Gas or Liquid.
The pressure relief or pop off point are set in accordance to
safety and capacity requirements.
ASME Section VIII: UG134(a)
When a single pressure relief device is used, the set pressure
marked on the device shall not exceed the maximum allowable
working pressure of the vessel.
Lifting Device as required by the ASME,
ASME Section VIII: UG136(3)
Each pressure relief valve on air, water at the valve inlet that
exceeds 140F (60C), excluding overpressure or relief events, or
steam service shall have a substantial lifting device which when
activated will release the seating force on the disk when the
pressure relief valve is subjected to a pressure of at least 75%
of the set pressure of the valve.
Under ASME code case 2203:
The lift lever may be omitted providing:
1. The user has a documented procedure and an associated
implementation program for the periodic removal of the relief
valve for inspection, testing, and repair.
2. The user specifies that no test lever be supplied.
The user shall obtain permission to omit the lifting lever
(device) from the authority having jurisdiction over the
installation of pressure vessel.
These rules apply to valves installed in ASME Section VIII
applications. All valves used in ASME Section I (Boiler)
applications require lifting levers except for those valves used
in organic fluid vaporizer service.
Aquatrol's Series 69 has the option of a handle wheel for field
Inlet and outlet sizes. Industry standards are Male Inlet and
Female outlet. Please specify if otherwise. Space or the valves
physical size may also be a consideration.
Refer to each listing for sizes, capacities, pressure
settings and applications.
See individual valves for information on ordering.
Contact us for further information or
to order by phone, email, or mail.
Pressure Setting Points
ASME Section VIII: UG134(d)(1)
The set pressure tolerance for pressure relief valves shall
not exceed +/- 2 psi for pressures up to and including 70 psi
and +/- 3% for pressures above 70 psi.
Aquatrol Valves are interchangeable with major safety valve
manufacturers. Contact us for
ASME Code - Section I
The pressure relief valve capacity for each boiler shall be
such that the pressure relief valve, or valves will discharge
all the steam that can be generated by the boiler without
allowing the pressure to rise more than 6% above the highest
pressure at which any valve is set and in no case to more than
6% above the maximum allowable working pressure.
ASME Code-Section VIII UG-125(c)
Other than unfired steam boilers, when a pressure relief
device is provided, it shall prevent the pressure from rising
more than 10% or 3 psi, whichever is greater, above the
maximum allowable working pressure.
(Check the ASME code books for more information.)
It is important to not oversize a relief valve by to
much. Typically, this will result in valve chatter or rapid
opening and closing of the valve disk. If chattering is
present, it could be more economical to use two valves.
For ASME calculations or further information
Contact us if you have any
questions or concerns about valve sizing.