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-ber
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 Identication 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-ber 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 ats 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 at-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) rst, 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 at-blade screwdriver, loosen counter-
clockwise and detach the plunger (23) from the stem (10).
G. Using your index nger, 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) rst, 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 ats 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 at-blade screwdriver, loosen counter-
clockwise and detach the plunger (22) from the stem (10).
H. With one hand, hold the carrier assembly rmly. 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 veried! 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 verication, tighten the locknut by turning clockwise until it is rmly-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 ow 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 backow preventer is installed in the supply piping.
ANSI / NSF 61-F and 61-G
ANSI / NSF 372
• Certied 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
