Flowserve 1878 Double-Disc Gate Valve - Manual (Page 8)

8
6.0
INSTALLATION INSTRUCTIONS
6.1
Lifting and Handling Requirements and Limitations
6.1.1 Good judgement should be exercised in selecting a lifting device that will
safely support the unit's weight.
6.2
Installation
6.2.1 Although the valves have been shipped in a clean condition, prior to
installing the valves, examine the lines and the valve ports for foreign matter
and clean them thoroughly if they have been exposed to the elements;
(BEFORE CLEANING IN THIS FASHION, CHECK AT THE SITE TO SEE
IF A SPECIFIC CLEANING PROCEDURE SHOULD BE FOLLOWED.)
Open the valves fully and flush them out with water if possible; otherwise
blow them out with air or steam.
In performing this cleaning procedure, the ports should be vertical and the
stem horizontal to assure complete removal of all matter that might have
accumulated during storage.
6.2.2 Ensure that there is no line sag at the point of installation. Eliminate any
pipeline deviation by the proper use of pipeline hangers or similar devices.
6.2.3 Where possible, install the valves with the stem vertical. When other
orientations are used, take care when disassembling the valve so that the
internals do not become damaged.
6.2.4 Remove the end protectors and clean the socket weld ends with a solvent
such as Acetone in preparation for welding the valve into the line. The
valves should then be blocked or slung into position with an apparatus that is
sufficient to hold the valve assembly weight while the valve is being welded
into the line. WELDING SHALL TAKE PLACE WITH THE DISC IN THE
OPEN POSITION.
6.3
Pre-Operational Checks
6.3.1 After installation the operation of manual valves should be verified by closing
the valve. The valve should seat tightly with less than 60 lbs. of force on the
handwheel rim. If the valve does not close tightly do not apply extra
leverage; instead refer to Para. 9.4 A and B.