TITLE:
NO.:
KEROTEST MODEL-1
REV.: 10
GATE VALVE
DATE: 7/12/07
OPERATIONS MANUAL
PAGE: 14 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
4.2 If gland and packing do not rise as nuts are loosened, continue to loosen nuts
until the top of the nuts are flush with the top of the all thread studs. Slowly
rotate the stem (10) in the same direction as closing the valve until the trapped
pressure begins to bleed. (If the bleeding pressure does not diminish, successful
seat shut-off has not been obtained.) Rotate stem in the direction for opening
valve until it contacts lower thrust washer.
Caution: Be careful not to break gate seal or packing will be subject of full
pressure and gas flow.
Retighten nuts on all thread studs and reinstall cap screws (3) in gland.
Reattempt seat shut off. When trapped pressure has been reduced to zero,
remove the two nuts and then gland (4). Rotate stem (10) in the same direction
as closing the valve until it is free from the wedge. Withdraw stem from valve.
(Lower thrust washer (12) may remain in the cover or on the stem (10)).
4.2.1 Remove top packing adapter (7), v-rings (8), and lower packing
adapter (9).
4.2.2 Replace lower thrust washer (12) in cover (if removed).
4.2.3 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).
4.2.4 Insert stem (10) in cover and rotate slowly by hand in the direction for
opening the valve. Continue rotation until stem shoulder (11) contacts
lower thrust washer (12).
Caution: Additional stem rotation will unseat the wedge resulting in
full gas pressure and flow.