Flowserve 800 Piston Lift Check Valve - Manual (Page 6)

6.2 Installation (Continued)
6.2.3 Extreme caution should be taken when installing check valves. The arrow
on the valve body indicates flow direction. Therefore, when installing a
check valve, place it so that the flow of the incoming fluid will open the
valve and return flow will close it. Check valves installed in reverse
position will stop the flow in the normal flow direction. Valves should be
installed in a horizontal run of pipe with the gasket retainer on top.
Maximum deviation from the horizontal should be ± 15
°
.
6.2.4 The valves should then be blocked or slung into position with apparatus
that is sufficient to hold the valve assembly weight while the valve is
being welded into the line. WELDING SHOULD TAKE PLACE WITH
THE DISC IN THE OPEN POSITION. This is particularly important for
valves with soft seats. Welding the valve with the disc closed will damage
the resilient seat material. This may require removal of the internals prior
to welding.
6.2.5 Remove the end protectors and clean the ends with a solvent such as
acetone in preparation to welding.
7.0
MAINTENANCE REQUIREMENTS
7.1 Preventative Maintenance
7.1.1 Check all bolts periodically to ensure tightness and to forestall possible
leaks.
7.2 Recommended Spare Parts
7.2.1 Recommended spare parts are pressure seal gasket (030), bonnet (002),
disc assembly (004 & 005, 245 & 306 if equipped with resilient seated
disc) and spring (429). The recommended quantity is 1 set for every 10
valves.
7.2.2 For consolidating spare parts (See 7.2.1), use the following guidelines:
- ½" thru 1" Piston Check Valves
Recommended spare parts are interchangeable throughout this size range.
Note that similar materials should be ordered for valve body type (i.e.
carbon steel bonnet for carbon steel valve).