TITLE:
NO.:
KEROTEST MODEL-1
REV.: 10
GATE VALVE
DATE: 7/12/07
OPERATIONS MANUAL
PAGE: 13 OF 35
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
.
SECONDARY REPACKING PROCEDURE – EARLY DESIGN (BEFORE 1988)
CONDITION 2
VALVE UNDER PRESSURE AND PRIMARY PROCEDURE WAS UNSUCCESSFUL
(REFER TO DRAWING ON PAGE 16)
1.
Close valve tightly with wrench.
2.
Remove nut (1) and operating square (2).
3.
Before proceeding, remember: If the valve was closed under pressure, the pressure is
trapped in the body cavity. When the stem or packing is removed, this pressure will
bleed from the body. Therefore, this procedure is not recommended for pressures in
excess of 90 PSIG. To prevent unsafe conditions, the following steps must be followed.
4.
Remove two of the cap screws (3). Replace with two all thread studs (size and length
recommended in table above). Thread all thread studs into cover until they bottom.
Install a nut on each stud and tighten. Remove all remaining cap screws (3).
4.1
Slowly and evenly loosen the two nuts on the all thread studs, watching that the
studs do not unthread from cover as the nuts are turned. If gland and packing
rise as nuts are loosened, continue to slowly loosen nuts until the trapped
pressure begins to bleed. (If the bleeding pressure does not diminish, successful
seat shut-off has not been obtained.)
Using the nuts on the studs, replace the packing and the gland. Reinstall the
remaining cap screws (3) and reattempt seat shut-off.
4.1.1
When trapped pressure has been reduced to zero, remove the two
nuts, and the gland (4). Upper thrust washer (6) may remain in gland
(4) or on stem (10), top packing adapter (7), v-rings (8), and lower
packing adapter (9).
4.1.2
Lubricate new parts with light oil and insert in packing chamber as
follows: Lower packing adapter (9), v-rings (8), and top packing
adapter (7).
4.1.3
Place upper thrust washer (6) on stem (10) if removed. Position
gasket (5) and gland (4) on cover. Insert cap screws (3) fully and
tighten. Place operating square (2) on stem, secure with nut (1).
