Flowserve Swing Check Valves 2.5-24 - Manual (Page 20)

Swing Check Valves FCD ADENIM0013-00
19
5.0 DISASSEMBLY
(Continued)
5.2
Pressure Seal Bonnet Valves (Fig 17)
5.2.1 Bonnet
A. Unbolt the capscrews (bonnet) (216) and remove the bonnet retainer (034). Set aside for use later.
B. Tap Ule 150nnet sharply to break the seal between it and the pressure seal gasket (030).The
bonnet will drop downward against its stop, uncovering the retaining ring (gasket) (033).
C. The retaining ring (gasket) (033) is comprised of four segments, one of which has a small drilled
hole. Remove this piece first. The groove in the top of the retaining ring gasket permits the use of a
pry bar or screwdriver in removing the segments. In some cases, it may be necessary to loosen the
segments by tapping with a hammer or bar.
D. The bonnet is now ready for removal from the body. The tight clearances between the body bonnet
and gasket, necessary for a reliable seal, require that the' bonnet be withdrawn squarely 'from the neck
bore. The slightest cocking of the bonnet during withdrawal can cause it to bind. Therefore, it is
recommended prior to removal, that the squareness of bonnet and gasket with respect to the body be
checked. This is most easily accomplished by measuring the distance between the top of the gasket
and top of the body neck. If the gasket is not square, it should be tapped with a brass rod until it is.
With large bonnets i(is a good idea as well to periodically check the squareness of bonnet as it 'is
being withdrawn. Binding any time during withdrawal indicates the bonnet has cocked. Further efforts
to force the, bonnet will generally make the situation worse. At the first sign of binding, stop and check
the squareness of the bonnet.
E. The preferred method of lifting the bonnet is by using slings attached to an eyebolt threaded into the
tapped hole in its center.
F. Following the above procedure will, in most cases, result in removal of the bonnet with little difficulty.
However, certain circumstances, such as installation of the valve in other than a horizontal orientation,
may cause complications. If greater difficulty is encountered, an Anchor/Darling service engineer
should be consulted. Excessive force which may damage critical surfaces should be avoided.
G. It is not normally recommended that the pressure seal gasket be reused. However, if a spare
gasket is not available, mark the gasket, bonnet and body prior to removal so that the gasket may be
reinstalled in its original orientation.
5.2.2 Disc Assembly
Anchor/Darling pressure seal swing check valves have been supplied with disc support configurations
as described in sections 5.1.2.1 and 5.1.2.3. Refer to these sections and section 5.1.2.4 for
disassembly procedures.