Consolidated 1900/P Series Safety Valves Instruction Manual
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V. Terminology for Safety Valves (Contd.)
Prevent dirt from
entering outlet port.
Make sure there is no
pressure in the valve
before disassembly.
• Seat
The seat is the junction between the nozzle which is fixed and the disc which
moves against the nozzle to obtain closure.
• Seat Leakage
Seat leakage test pressure is the specified inlet static pressure at which a
quantitative seat leakage test is performed in accordance with a standard
procedure.
• Set Pressure
Set pressure is the inlet pressure at which the valve has been adjusted to
open under service conditions.
For gas and vapor service - when the valve pops.
For liquid service - when the valve begins to discharge a continuous stream.
• Simmer
Characterized by the audible/visual passage of a fluid across the seating
surfaces just prior to opening. The difference between this start to open
pressure and the set pressure is simmer.
For gas service valves, simmer is leakage just prior to opening.
For liquid service valves, simmer is the noncontinuous flow (drops) just prior
to becoming continuous.
• Valve Trim
Includes the disc and nozzle.
VI. Handling and Storage
1. Each valve should be carefully inspected after uncrating to be sure the valve
has not been damaged during transit.
2. Flanged valves, either crated or skidmounted, should always be kept with the
inlet flange down, i.e. never laid on their side, to prevent misalignment and
damage to internals.
3. Valves should be stored in a dry environment to protect them from the
weather. They should not be removed from the skids or crates until
immediately prior to installation.
Handle carefully.
Do not drop or strike.
