Typical installation, Service and replacement parts, Disassembly – Watts LF800M4QT User Manual
Page 2: Reassembly, Freeze protection guidelines, Notice

Typical Installation
Using TWS Hydrant
NOTICE
PVB's must be installed a minimum of 12" (305mm) above the highest
point of water in the sprinkler system. (See Fig. 1)
Service and Replacement Parts
Internal parts can be removed, repaired or inspected without removing the valve from the piping.
Disassembly
1. Shut off the supply pressure and drain the valve.
2. Remove the two hood screws and the hood.
3. Place a wrench on the parallel flats of bonnet and stem assembly.
Turn counter clockwise and remove.
4. Remove the vent assembly.
5. Press down on the spring retainer and disengage it from the retaining
lugs. Then turn 90° and remove.
6. Remove the spring retainer and spring. Note that the large diameter of
the spring is down on the guide assembly.
7. Remove the check disc holder and guide assembly.
8. Disassemble the check disc holder assembly.
9. Remove seat (if required) by turning counterclockwise.
Reassembly
Reassemble in the reverse order utilizing the new parts from the repair kit.
To
Sprinklers
Key
Drain Port
or
Blow Down
Water
Supply
Watts TWS
TWS with Watts Series 800M4/LF800M4
Pressure Vacuum Breaker
Watts 800M4QT/LF800M4QT
1" - 2" (25 - 50mm)
Watts 800M4QT/LF800M4QT
1
⁄
2
",
3
⁄
4
" (15 - 20mm)
Watts reserves the right to change or modify product design, construction, specifica-
tions, or materials without prior notice and without incurring any obligation to make
such changes and modifications on Watts products previously or subsequently sold.
†
Fits 800M4FR/LF800M4FR Model
*The wetted surface of this product contacted by consumable
water contains less than 0.25% of lead by weight.
RP/IS-800M4QT 1318
EDP# 1915087
© 2013 Watts
USA: Tel: (978) 688-1811 • Fax: (978) 794-1848 • www.watts.com
Canada: Tel: (905) 332-4090 • Fax: (905) 332-7068 • www.watts.ca
Limited Warranty: Watts Regulator Co. (the “Company”) warrants each product to be free from defects in material and workmanship under normal usage for a period of one year from the date of
original shipment. In the event of such defects within the warranty period, the Company will, at its option, replace or recondition the product without charge.
THE WARRANTY SET FORTH HEREIN IS GIVEN EXPRESSLY AND IS THE ONLY WARRANTY GIVEN BY THE COMPANY WITH RESPECT TO THE PRODUCT. THE COMPANY MAKES NO OTHER
WARRANTIES, EXPRESS OR IMPLIED. THE COMPANY HEREBY SPECIFICALLY DISCLAIMS ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
The remedy described in the first paragraph of this warranty shall constitute the sole and exclusive remedy for breach of warranty, and the Company shall not be responsible for any incidental, special
or consequential damages, including without limitation, lost profits or the cost of repairing or replacing other property which is damaged if this product does not work properly, other costs resulting
from labor charges, delays, vandalism, negligence, fouling caused by foreign material, damage from adverse water conditions, chemical, or any other circumstances over which the Company has no
control. This warranty shall be invalidated by any abuse, misuse, misapplication, improper installation or improper maintenance or alteration of the product.
Some States do not allow limitations on how long an implied warranty lasts, and some States do not allow the exclusion or limitation of incidental or consequential damages. Therefore the above
limitations may not apply to you. This Limited Warranty gives you specific legal rights, and you may have other rights that vary from State to State. You should consult applicable state laws to
determine your rights.
SO FAR AS IS CONSISTENT WITH APPLICABLE STATE LAW, ANY IMPLIED WARRANTIES THAT MAY NOT BE DISCLAIMED, INCLUDING THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED IN DURATION TO ONE YEAR FROM THE DATE OF ORIGINAL SHIPMENT.
A Watts Water Technologies Company
WARNING: This product contains chemicals known to the
State of California to cause cancer and birth defects or
other reproductive harm.
For more information: www.watts.com/prop65
1. Close main shutoff valve.
2. Open upstream drain, test cocks and isolation ball
valves to depressurize line.
3. Purge with pressurized line.
4. Leave test cocks and isolation ball valve handles in
45° angle to drain ball valves and prevent casting
damage.
Freeze Protection Guidelines
Purging of a PVB Assembly with Pressurized Air
Flow
Upstream (Inlet) Drain
Outlet Drain
Valve
12" Minimum Clearance
Above the Highest Point of
Downstream Piping
Zone Control
Valve Pit Sprinkler System
Piping
Union
Main Shutoff Valve
▼
▼
For repair kits and parts, refer to our Backflow
Prevention Products Repair Kits & Service Parts
price list PL-RP-BPD found on
www.watts.com.