Flowserve 1878 Piston Check Valve - Manual (Page 4)

1878 Piston Check Valves FCD ADENIM0005-00
4
1.0 Physical Description And Operation Of Equipment
1.1 Piston Check Valves (Figures 1 & 2 - See Section 11.0)
Piston Lift Check valves are generally used in applications where pressure drop through the valve is not critical,
although Flowserve piston check valves have a relatively low pressure drop.
These small piston lift check valves include a return spring to facilitate closing. All Flowserve piston check valves
have body guided discs to provide resistance to wear, thus, insuring a longer life. An equalizing hole is provided in
the disc as a drain for condensate in steam valves.
A dual seat may be supplied which provides a hard surface for high differential pressure sealing and a resilient seat
for sealing during low differential pressure.
These instructions are being furnished to the customer for use in the installation, operation and maintenance of the
1878 pressure class series piston lift check valves.
2.0 Design Conditions
Refer to the applicable drawing(s) in Section 12.0 of this manual.
3.0 Operating Conditions
Refer to the applicable drawing(s) in Section 12.0 of this manual.
4.0 Test Conditions
4.1 Each valve covered by this manual has received the following hydrostatic tests:
4.1.1 Shell hydrostatic test at 1.5 times the 100
°
F pressure rating.
4.1.2 A seat leakage and disc closure test at 110% of the 100
°
F pressure rating.