Kerotest MODEL-1, Operation Manual

Page: 38 / 48

TITLE:
NO.:
KEROTEST MODEL-1 REV.: E
GATE VALVE BONNET LEAK
DATE: 7/12/07
REPAIR PROCEDURE PAGE: 3 OF 13
This report is the property of Kerotest Manufacturing Corp. 5500 Second Avenue, Pittsburgh, PA 15207 and may not be
copied by any means without the expressed written consent of Kerotest. It is intended for the sole purpose of helping
Kerotest customers evaluate Kerotest products and may not be released to any third party or otherwise used in any
manner injurious to the interests of Kerotest
.
1. When a bonnet leak is detected,
do not attempt to re-tighten the existing bonnet bolts and,
do not attempt to operate valve, since loads applied could cause damaged bolts to break.
2. If the valve can be depressurized, remove bonnet and replace gasket and existing bonnet
bolts after depressurization with only factory authorized parts. Refer to Enclosure 1 for
removal of broken bolts. Kerotest part numbers for bonnet bolts and gaskets are listed
below. These parts are available from Kerotest at no charge to the customer.
Valve Size Bolt Part
Numbers
Description Gasket
Part Numbers
1-1/4" and
Smaller 88370085 A574 Socket HD
3/8" – 16 x 1-1/4 Long 88231220
2" 88232541 A574 Socket HD
7/16 – 14 x 1-1/4 Long 88231865
3" 88231303 A574 Socket HD
1/2 – 13 x 1-1/2 long 88232087 (275 & 500)
88232186 (720)
4"
(275 & 500) 88231303 A574 Socket HD
1/2 – 13 x 1-1/2 Long 88232350 (275 & 500)
4"
(720) 88231329 A574 Socket HD
1/2 – 13 x 1-3/4 Long 88232384 (720)
6" 88231329 A574 Socket HD
1/2 – 13 x 1-3/4 Long 88232509 (275 & 500)
88232525 (720)
8" 88232434 A574 Socket HD
5/8 – 11 x 2-1/4 long 88232558
10" 88232236 A574 Socket HD
3/4 – 10 x 3-1/4 Long 88231709
12" 88232236 A574 Socket HD
3/4 – 10 x 3-1/4 Long 88231766
Coat new bonnet gaskets with Slic-Tite TFE paste.
During bolt replacement, tighten bolts in proper sequence and to the torque values listed in
Enclosure 2.
3. If valve cannot be depressurized, remove and replace bolts one at a time (see Item 2 for
bolt part number). When replacing bonnet bolts on 1-1/4 size valves, a special Kerotest
bolt replacement fixture and procedure must be used. This is shown in Enclosure 3.