Flowserve Swing Check Valves 2.5-24 - Manual (Page 29)

Swing Check Valves FCD ADENIM0013-00
28
6.0 ASSEMBLY
(Continued)
6.2.2
Bonnet
Once the hinge - disc assembly is in place, the bonnet (002) can be inserted into the neck. Care must
be taken in lowering the bonnet. It is again very important to keep the bonnet from cocking, as it is
lowered into the body. If it does bind, the bonnet must be straightened before insertion can continue.
Measuring from the bonnet bolting surface to the top of the body is the simplest way to detect cocking.
With the bonnet resting on the counterbore in the neck, a new gasket (030) and the spacer ring (032)
can be inserted. In that the gasket may also cock, it must be inserted with care. Once these are in
place, the four-piece gasket retainer (033) can be put into place. It is important to remember that the
piece with the drilled hole must be positioned last. If the valve is installed in other than a horizontal
position, it may be necessary to orient or hold the retainer such that the pieces stay in place until the
bonnet is moved into its raised position. Prior to installing the bonnet retainer, the pipe plug (336)
should be removed. A threaded rod, long enough to extend from the top of the bonnet above the body
neck should be inserted into the tapped hole in the center of the bonnet. The bonnet retainer (034)
can now be lowered over the top of the rod and set into position. Using the threaded rod the bonnet
can be raised into its position and the bonnet capscrews (216) inserted through the retainer and
threaded into their holes in the bonnet. By turning each capscrew a couple of turns, proceeding to the
adjacent capscrew, turning it and then repeating this around the bolt circle, the bonnet will be raised
squarely until it is firmly in contact with the gasket. Note that while the capscrews need not be torqued
to a specific value to maintain a tight seal at system pressures, they should be tightened with wrench
to insure good gasket-body-bonnet seal contact before the full pressure is reached.
FIGURE 17