Lead Free Water Pressure Reducing Valves (PRV)
Models T-6800NL, T-6801NL, T-6802NL and T-6803NL Installation Instructions
T-6803NL
Cut-away
No.
Part
Material
Specification
1
Adjustment bolt
Cadmium Plated Steel
ASTM A283-D
2
Lock Nut
Cadmium Plated Steel
AISI-1010
3
Bonnet
Cast brass or Polycarbonate resin, glass-fiber
reinforced
ASTM B584 C85700 (brass)
Commercial grade (resin)
4
Anti-friction ring
Stainless steel
AISI 304
5
Spring disc
Zinc Plated Steel
ASTM A283-D
6
Spring
Cold Drawn Steel Wire
ASTM A227M-91
7
Diaphragm nut
Cadmium Plated Steel
AISI-1010
8
Diaphragm disc
Zinc Plated Steel
ASTM A283-D
9
Diaphragm
Reinforced NBR
(Buna-N) Rubber
Commercial grade,
Nylon-reinforced
10
Stem
Lead-Free Forged Brass
UNS Alloy C46400
11
Check-ball
NBR (Buna-N) Rubber
Commercial grade
12
Ball retaining screw
Stainless Steel
AISI 304
13
Stem O-ring
NBR (Buna-N) Rubber
Commercial grade
14
Body
Lead-Free Cast Brass
UNS Alloy C87850 Eco Brass
15
Union nut
Cast Brass
ASTM B584 UNS C85700
16
Union tailpiece
Lead-Free Forged Brass
UNS Alloy C46400
17
Union washer
NBR (Buna-N) Rubber
Commercial grade
18
Strainer screen
Stainless Steel
AISI 304
19
Seat O-ring
NBR (Buna-N) Rubber
Commercial grade
20
Plunger washer
Stainless Steel
AISI 304
21
Plunger seat
NBR (Buna-N) Rubber
Commercial grade
22
Plunger
Lead-Free Forged Brass
UNS Alloy C46400
23
Identification plate
Aluminum
ASTM B209 1100
24
Carrier sleeve
Polycarbonate resin
Commercial grade
25
Spring washer
Cold-drawn steel
ASTM A227M-91
26
Body sleeve O-ring
NBR (Buna-N) Rubber
Commercial grade
27
Upper sleeve O-ring
NBR (Buna-N) Rubber
Commercial grade
28
Thrust collar
Polycarbonate resin, glass-fiber reinforced
Commercial grade
29
Plug
Lead-Free Forged Brass
UNS Alloy C46400
30
Plug O-ring
NBR rubber
Commercial grade
C. Loosen and detach the bonnet (3) by un-threading it counter-clockwise.
D. Remove the following components that are contained within the bonnet: anti-friction ring (4), spring disc (5)
and spring (6).
E. With a pair of pliers, grip the diaphragm nut (7),
from the top, using the tips of the pliers’ jaws
(
don’t
grip the nut’s flats from the side, as if loosening the nut).
F. Firmly pull out the entire carrier assembly from the body of the valve. The carrier assembly is comprised of
parts 7, 8, 9, 10, 11, 12, 13, 18 (strainer screen) 19, 20, 21, 22, 24, 25 and 26 assembled as one piece. See
Figure 4.
G. Hold the diaphragm nut (7) with a 13 MM wrench. With a large flat-blade screwdriver, loosen counter-
clockwise and detach the plunger (22) from the stem (10).
H. Remove the plunger washer (20) and plunger seat (21) by separating them from the plunger. Replace with
the correct seat material and size. Re-assembly is in the reverse-order.
To replace the diaphragm (9):
Model T-6800NL
A. Shut off water supply and relieve system pressure.
B. Loosen locknut (2) first, and then adjustment bolt (1) by turning both counter-clockwise at least two
complete revolutions.
C. Loosen and detach the bonnet (3) by un-threading it counter-clockwise.
D. Remove the following components that are contained within the bonnet: anti-friction ring (4), spring disc (5)
and spring (6).
E. Loosen and remove the service cap (25) by turning counter-clockwise.
F. Hold the diaphragm nut (7) with a 17 MM wrench. With a large flat-blade screwdriver, loosen counter-
clockwise and detach the plunger (23) from the stem (10).
G. Using your index finger, push the bottom of the stem (10, where the plunger was installed) upward to detach
the stem and diaphragm (9) assembly out of the valve’s body.
H. Secure the 22 MM hex-shaped portion of the stem (10) that is directly underneath the diaphragm (9) using
a 22 MM deep-well socket and ratchet or breaker-bar. Prevent the stem from rotating as you loosen counter-
clockwise, and detach the diaphragm nut (7) using a 17 MM wrench.
I. Remove the spring washer (29), diaphragm disc (8) and diaphragm (9) by lifting them off of the stem.
Replace with the correct diaphragm. Re-assembly is in the reverse-order. Apply one drop of low-strength
thread-locking compound to the male threads of the stem prior to attaching the diaphragm nut.
Models T-6801NL, T-6802NL and T-6803NL
A. Shut off water supply and relieve system pressure.
B. Loosen locknut (2) first, and then adjustment bolt (1) by turning both counter-clockwise at least two
complete revolutions.
C. Loosen and detach the bonnet (3) by un-threading it counter-clockwise.
D. Remove the following components that are contained within the bonnet: anti-friction ring (4), spring disc (5)
and spring (6).
E. With a pair of pliers, grip the diaphragm nut (7),
from the top, using the tips of the pliers’ jaws
(
don’t
grip the nut’s flats from the side, as if loosening the nut).
F. Firmly pull out the entire carrier assembly from the body of the valve. The carrier assembly is comprised of
parts 7, 8, 9, 10, 11, 12, 13, 18, 19, 20, 21, 22, 24, 25 and 26 assembled as one piece. See Figure 4.
G. Hold the diaphragm nut (7) with a 13 MM wrench. With a large flat-blade screwdriver, loosen counter-
clockwise and detach the plunger (22) from the stem (10).
H. With one hand, hold the carrier assembly firmly. With the thumb of the free hand, push the bottom of the
stem (10) and diaphragm (9) out of the carrier sleeve (24)
I. Secure the 18 MM hex-shaped portion of the stem (10) that is directly underneath the diaphragm (9) using an
18 MM deep-well socket and ratchet or breaker-bar. Prevent the stem from rotating as you loosen counter-
clockwise, and detach the diaphragm nut (7) using a 13 MM wrench.
J. Remove the spring washer (25), diaphragm disc (8) and diaphragm (9) by lifting them off of the stem.
Replace with the correct diaphragm. Re-assembly is in the reverse-order. Apply one drop of low-strength
thread-locking compound to the male threads of the stem prior to attaching the diaphragm nut.
Adjustment:
CAUTION!
Post-adjusted pressure
MUST
be verified! A pressure gauge should be installed downstream to
verify the pressure setting. All models are
factory pre-set at 50 psi
.
To adjust the pressure:
1. With a 17 MM (13 MM on Models T-6801NL, T-6802NL & T-6803NL) open-end wrench, loosen the locknut
(2) by turning counter-clockwise.
2. With a 17 MM (13 MM on Models T-6801NL, T-6802NL & T-6803NL) wrench or socket, turn the adjustment
bolt (1) CLOCKWISE to INCREASE the outlet pressure or COUNTER-CLOCKWISE to DECREASE outlet
pressure.
3. After adjustment and pressure verification, tighten the locknut by turning clockwise until it is firmly-seated
against the top of the bonnet. DO NOT OVER-TIGHTEN!
Maximum inlet pressure: 300 CWP
Maximum temperature: 180° F
Reduced pressure adjustment range: 25 to 75 psi.
By-pass Feature:
All models feature a built-in thermal expansion by-pass. This feature prevents downstream pressure from
rising to more than 10 psi above the supply pressure.
Troubleshooting - High System Pressure:
WARNING!
All plumbing components within the distribution system
MUST
be protected against excess
pressure, where the addition of a pressure relief valve of the appropriate type, may be required. The installer
is responsible for knowing and complying with all local or National code requirements pertaining to pressure
relief.
If the downstream system pressure is higher than the set pressure under no flow conditions, the cause could
be thermal expansion, pressure creep or dirt/debris on the seat.
Thermal expansion occurs whenever water is heated in a closed system. The system is closed when supply
pressure exceeds 150 psi, or a check valve or backflow preventer is installed in the supply piping.
ANSI / NSF 61-F and 61-G
ANSI / NSF 372
• Certified to ASSE
1003 Standard
Note: Shaded components make up the carrier assembly. See step F.
Please contact Legend Technical at 800-752-2082
with additional questions.
T-6801NL
Cut-away
Figure 4
T-6802NL
Cut-away
Rev. 12.15
