TG 5 Wilkins Instructions
User Manual: TG-5
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1
Model TG-5
5 Valve Backow Prevention Assembly Test Kit
a
®
company
a
®
company
Testing Procedures
REDUCED PRESSURE TYPE BACKFLOW PREVENTER (5 Valve)
Note: It is the tester's responsibility to determine if this procedure is accepted by local
authorities.
TEST #1
Purpose: To test the operation of the pressure differential relief valve.
Requirement: The differential pressure relief valve must operate to maintain the zone
between the two check valves at least 2 psi less than the supply pressure.
Procedure:
A. Open #4 test cock to establish ow through the unit, then ush water through test
cocks #1, #2, and #3 by opening and closing each test cock one at a time to eliminate
foreign material. Be careful not to dump the relief valve during this process (open #2 test
cock slowly). Close test cock #4.
B. Install test ttings.
C. Install hose from the high side of the differential pressure gauge to the #2 test cock.
D. Install hose from the low side of the differential pressure gauge to the #3 test cock.
E. Open test cock #3 slowly and bleed all air from the hose and gauge by opening the
low side bleed needle valve. Maintain the low side bleed needle valve in the open position
while slowly opening test cock #2. Open the high side bleed needle valve to bleed the
hose and gauge. Close the high side bleed needle valve then close the low side bleed
needle valve after the gauge has pinned at the upper end of the scale.
F. Close #2 shutoff valve.
G. Observe the apparent pressure drop across the #1 check valve. If the gauge needle
drops to the low end of the scale and the differential pressure relief valve continuously
discharges, then the #1 check valve is leaking.
H. Open the high side control needle valve approximately one turn, then slowly open
the low side control needle valve no more than one quarter turn to bypass water from
the #2 test cock to the #3 test cock.
I. Watch the pressure differential drop slowly while observing the relief valve discharge
port. When water is observed leaking from the relief valve discharge port, note the relief
valve opening point.
J. Close needle valves.
TEST #2
Purpose: To test the #2 check valve for tightness against reverse ow.
Requirement: The #2 check valve shall be tight against reverse ow.
Procedure:
A. Maintain #2 shutoff valve in the closed position from test #1.
B. Vent all of the air through the bypass hose by opening both the high side control
needle valve and the bypass needle valve. Close the bypass needle valve ONLY.
C. Install bypass hose from the differential pressure gauge to the #4 test cock. Open
the #4 test cock.
D. Bleed water from the “zone” by opening the low side bleed needle valve on the gauge
in order to re-establish the normal reduce pressure within the zone. Once the gauge
reaches the high end of the scale close the low side bleed needle valve.
E. Open the bypass needle valve. If the indicated pressure differential remains steady,
then the #2 check valve is reported as “closed tight”. If the pressure differential falls to the
relief valve opening point and leaks steadily, then check for disc compression by opening
the low side bleed needle valve until the needle is pinned at upper end of scale. Close
low side bleed needle valve. If the indicated pressure differential remains steady, then
the #2 check is reported as "closed tight". If the pressure differential falls to the relief
valve opening point again and leaks steadily, then the #2 check is noted as "leaking" and
Test #3 below cannot be completed. If the pressure differential drops but stops above
the relief valve opening point, the #2 check valve can still be reported as "closed tight".
TEST #3
Purpose: To determine the tightness of #1 check valve and to record the static pressure
drop across the #1 check valve.
Requirement: The static pressure drop across #1 check valve should be at least 3 psi
greater than the relief valve opening point (Test #1). This 3 psi “buffer” will prevent the
relief valve from discharging during small uctuations in upstream line pressure.
A “buffer” of less than 3 psi does not im-
ply a leaking #1 check valve (i.e. allowing
backow) but rather is an indication of
how well the #1 check valve is holding.
Procedure:
A. With the bypass hose connected to test
cock #4 as in step “C” of Test #2, bleed
water from the “zone” through the low side
bleed needle valve on the gauge until the
needle reaches the high end of the scale.
B. Close the low side bleed needle valve.
After the gauge needle settles, the steady
state pressure differential indicated (needle
is not falling on the gauge) is the actual
static (i.e., no ow) pressure drop across
#1 check valve, and is to be recorded as
such.
C. Close all test cock valves, open #2 shut-
off valve and remove all test equipment.
LOW SIDE
VALVE
(GREEN)
NEEDLE
NEEDLE
VALVE
(GREEN)
HOSE
LOW SIDE
CONTROL
LOW SIDE
BLEED
HIGH SIDE
VALVE
(RED)
NEEDLE
CONTROL
NEEDLE
VALVE
(RED)
HOSE
HIGH SIDE
HIGH SIDE
BLEED
NEEDLE
VALVE
(BLACK)
BYPASS
HOSE
BYPASS
2WILKINS, a ZURN company
1747 Commerce Way, Paso Robles, CA 93446 Phone:805/238-7100 Fax:805/238-5766
a
®
company
ISTG-5 (REV. 7/08)
WARRANTY: WILKINS Valves are guaranteed against defects of material or workmanship when used for the services recom-
mended. If in any recommended service, a defect develops due to material or workmanship, and the device is returned, freight
prepaid, to WILKINS within 12 months from date of purchase, it will be repaired or replaced free of charge. WILKINS' liability shall
be limited to our agreement to repair or replace the valve only.
PRESSURE VACUUM BREAKER
Note: It is the tester’s responsibility to determine if this procedure
is accepted by local authorities.
All of tests below are to be performed with differential gauge and
hoses held at same level as valve being tested.
TEST #1
Purpose: To determine the air inlet valve opening point
Requirement: The air inlet valve shall open when the pressure
in the body is no less than 1.0 psi above atmospheric pressure.
The air inlet valve shall be fully open when the water drains from
the body.
Procedure:
A. Remove air inlet canopy. Open and ush water through test
cocks #1 and #2 by opening and closing each test cock one at
a time.
B. Install test tting on test cocks.
C. Attach high side hose of the differential pressure gauge to the
#2 test cock.
D. Open test cock #2 and bleed all air from the hose and gauge
by opening the high side bleed needle valve, then close the high
side bleed needle valve.
E. Close #2 shutoff valve, then close #1 shutoff valve.
F. Holding the pressure differential gauge at the level of the as-
sembly being tested, slowly open high side bleed needle valve
no more that one quarter turn. Do not let pressure differential
reading drop too quickly. Record the reading on the gauge when
the air inlet valve opens. Fully open the high side bleed needle
valve to drain water from the body. Make sure that air inlet valve
has dropped to the fully open position.
G. Close #2 test cock and remove hose from tting. Open #1
shutoff valve.
TEST #2
Purpose: To determine the static pressure drop across the check
valve.
Requirement: The static pressure drop across check valve shall
be at least 1.0 psid.
Procedure:
A. Attach hose from the high side of the differential pressure
gauge to the #1 test cock and open #1 test cock.
B. Bleed all air from the hose and gauge by opening the high
side bleed needle valve, then close the high side bleed needle
valve.
C. Close #1 shutoff valve.
D. Holding the pressure differential gauge at the level of the as-
sembly being tested, open test cock #2. After water stops running
out of test cock #2 and the gauge stabilizes, the reading on gauge
is the static pressure drop across the check valve.
E. Close both test cocks and remove hoses and ttings. Slowly
open #1 shutoff valve then the #2 shutoff valve.
F. Replace air inlet valve canopy.
DOUBLE CHECK VALVE BACKFLOW PREVENTER
Note: It is the tester’s responsibility to determine if this procedure
is accepted by local authorities.
TEST #1
Purpose: To determine the static pressure drop across #1 check.
Requirement: The static pressure drop across check valve #1
shall be at least 1.0 psid.
Procedure:
A. Open and ush water through test cocks #1, #2, #3 & #4 by
opening and closing each test cock one at a time.
B. Install test tting on test cock #2.
C. If test cock #3 is not at the highest point of the check valve
body, then a vertical tube or pipe must be installed on test cock
#3 so that it rises to the top of the check valve body.
D. Attach high side hose of the differential pressure gauge to the
#2 test cock.
E. Open test cock #2 and bleed all air from the hose and gauge
by opening the high side bleed needle valve, then close the high
side bleed needle valve. If a tube is attached to test cock #3, open
test cock #3 to ll the tube, then close test cock # 3.
F. Close #2 shutoff valve, then close #1 shutoff valve.
G. Slowly open test cock #3. Hold differential gauge at level of
water in sight tube. After water stops running out of test cock #3
and the gauge stabilizes record the reading on gauge as the static
pressure drop across the #1 check.
H. Close test cocks #2 & #3, and open #1 shutoff valve.
TEST #2
Purpose: To determine the static pressure drop across check
valve #2.
Requirement: The static pressure drop across check valve #2
shall be at least 1.0 psid.
Procedure:
A. Attach test tting and hose from the high side of the differential
pressure gauge to the #3 test cock.
B. If test cock #4 is not at the highest point of the check valve
body, then a vertical tube or pipe must be installed on test cock
#4 so that it rises to the top of the check valve body.
C. Open test cock #3, and bleed all air from the hose and gauge
by opening the high side bleed needle valve and then closing the
high side needle valve. If a tube is attached to test cock #4, open
test cock #4 to ll the tube, then close test cock #4.
D. Close #1 shutoff valve.
E. Slowly open test cock #4. Hold differential gauge at level of
water in sight tube. After water stops running out of test cock
#4 and the gauge stabilizes, record the reading on gauge as the
static pressure drop across the #2 check.
F. If the water at test cock #4 recedes, there is a leaking #2
shutoff valve. Move the gauge to the center line of the assembly
and record the gauge reading as the pressure differential across
the #2 check valve.
G. Close all test cocks and remove all test equipment.
H. Remove all ttings. Open shutoff valve #1, then slowly open
shutoff valve #2.
