Watts AMES LF920GD Series Guide

ES-A-ACV-LF920GD
Engineering Specification, Installation, Operation and Maintenance
Pressure Relief, Sustaining, or Backpressure Control Valve
Sizes: 1¼" to 24"
NOTICE
For Australia and New Zealand: Pipeline strainers should be
installed between the upstream shutoff valve and the inlet of
the backflow preventer.
It’s important that this device be tested periodically in compli-
ance with local codes, but at least once per year or more as
service conditions warrant. If installed on a fire sprinkler system,
all mechanical checks, such as alarm checks and backflow
preventers, should be flow tested and inspected internally in
accordance with NFPA 13 and NFPA 25.
WARNING
!
Read this Manual BEFORE using this equipment.
Failure to read and follow all safety and use information
can result in death, serious personal injury, property
damage, or damage to the equipment.
Keep this Manual for future reference.
Local building or plumbing codes may require modifica-
tions to the information provided. You are required to
consult the local building and plumbing codes prior
to installation. If the information provided here is not
consistent with local building or plumbing codes, the
local codes should be followed. This product must be
installed by a licensed contractor in accordance with
local codes and ordinances.
WARNING
!
Need for Periodic Inspection/Maintenance: This product
must be tested periodically in compliance with local codes,
but at least once per year or more as service conditions
warrant. All products must be retested once maintenance
has been performed. Corrosive water conditions and/or
unauthorized adjustments or repair could render the product
ineffective for the service intended. Regular checking and
cleaning of the product’s internal and external components
helps assure maximum life and proper product function.
WARNING
!LF920GD
Series LF920GD / LF620GD
Table of Contents Page
Engineering Specifications
ACV Schematic ........................................2
Basic Valves ...........................................3
Standard Components...................................7
Optional Components ..................................10
Installation, Operation and Maintenance
Installation............................................14
Valve Servicing Dimensions ..............................14
Setting the Pressure Controls ............................15
ACV Maintenance Schedule .............................17
Troubleshooting Guide ..................................18
Valve Disassembly Instructions ....................... 19
Submittal Package
Watts product specifications in U.S. customary units and metric are approximate and are provided for reference only. For precise measurements, please contact
Watts Technical Service. Watts reserves the right to change or modify product design, construction, specifications, or materials without prior notice and without
incurring any obligation to make such changes and modifications on Watts products previously or subsequently sold.

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ES-A-ACV-LF920GD 2115 © 2021 Watts
Pressure Relief, Sustaining or Backpressure Control Valve
Full Port Ductile Iron Single Chamber Valve
Engineering Specification
Features
• Opens when upstream pressure is above setpoint
• Closes when upstream pressure is below setpoint
• Adjustable Closing Speed
• When installed on branch of tee, acts as Pressure Relief Valve
• When installed between two pressure zones, acts as Pressure
Sustaining Valve
• When installed on discharge of a pump, acts as Backpressure
Control Valve
• Setpoint is adjustable
Options and Accessories
{FC – Flo-Clean Strainer (Standard 1¼" – 4")
{Y – Y-Strainer (Replaces Flo-Clean)
{AOS – Adjustable Opening Speed (Standard 1¼" – 4")
{P – Position Indicator
{L – Limit Switch
Standard Components
1
X
XX
Y/FC
3
2
(AOS)
CLOSES VALVE
OPENS VALVE
FLOW
P/L
1 – Main Valve (905GD - Single Chamber)
2 – Relief / Sustaining Control
3 – Adjustable Closing Speed
X – Isolation Cocks
LEAD FREE*
The information contained herein is not intended to replace the full
product installation and safety information available or the experi-
ence of a trained product installer. You are required to thoroughly
read all installation instructions and product safety information
before beginning the installation of this product.
NOTICE
*The wetted surface of this product contacted by consumable water
contains less than 0.25% of lead by weight.
Operation
The Pressure Relief, Sustaining or Backpressure Automatic Control
Valve (ACV) is designed to permit flow when upstream pressure
is above the adjustable setpoint of the control pilot, and throttle
toward closed when upstream pressure falls below the adjustable
setpoint. It is controlled by a normally closed control pilot designed
to: 1) Open (allowing fluid out of the main valve cover chamber)
when upstream pressure is above the adjustable setpoint, and,
2) Close (allowing fluid to fill the main valve cover chamber) when
upstream pressure is below the adjustable setpoint. An increase in
upstream pressure causes the valve to modulate toward an open
position. A decrease in upstream pressure causes the valve to
modulate toward a closed position.
When the valve is installed "off the main line" on the branch of a
tee, it serves as a Pressure Relief Control Valve. The valve is nor-
mally closed, and quickly opens when upstream pressure exceeds
the pilot setting, relieving pressure, commonly discharging to a
storage reservoir, pump suction, or atmosphere. When upstream
pressure is lowered below the pilot setting, the valve closes at a
controlled, adjustable rate.
When the valve is located "in line" connecting two distribution
zones, the valve acts as a Pressure Sustaining Control Valve.
When pressure in the upstream zone falls below the pilot setting,
the valve modulates toward a closed position, sustaining pres-
sure in the upstream zone. The valve will close, if necessary, until
upstream pressure is above the pilot setting. The valve should be
specified to include the optional opening speed control and posi-
tion indicator when used for Pressure Sustaining applications.
When the valve is installed "in line" on the discharge of a pump, it
acts as Backpressure Control Valve. When pump discharge pres-
sure falls below the pilot setting, the valve modulates toward a
closed position, increasing backpressure against the pump. The
valve should be specified to include the optional opening speed
control when used for Backpressure applications.
Series LF920GD

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ES-A-ACV-LF920GD 2115 © 2021 Watts
Threaded = 400psi (27.6 bar)
150# Flanged = 250psi (17.2 bar)
300# Flanged = 400psi (27.6 bar)
Grooved End = 400psi (27.6 bar)
Operating Pressure
M Series Basic Valves
Pressure Relief, Sustaining or Backpressure Control Valve
Full Port Ductile Iron Single Chamber Basic Valve
Standard Materials
Body and Cover: Ductile Iron ASTM A536
Coating: NSF Listed Fusion Bonded Epoxy
Lined and Coated
Trim: 316 Stainless Steel
Elastomers: Buna-N (standard)
EPDM (optional)
Viton
™
(optional)
Nut, Spring and Stem: Stainless Steel
Anti-Scale (Optional): Xylan Coated Stem and Seat
Viton™ is a trademark of The Chemours Company FC, LLC
ACV Schematic - Series LF920GD
This Ames Automatic Control Valve (ACV) is a full port, single
chamber basic valve that incorporates a one-piece disc and dia-
phragm assembly. This assembly is the only moving part within
the valve allowing it to open, close, or modulate as commanded
by the pilot control system.
Ames ACV Main Valves are Lead Free. The Ames ACV piloting
system contains Lead Free* components, ensuring all of our con-
figurations are Lead Free compliant.
Globe Pattern Single Chamber Basic Valve (905GD)
Angle Pattern Single Chamber Basic Valve (905AD)
Globe Flanged Angle Flanged
Globe Threaded Angle Threaded
Globe Grooved End Angle Grooved End
Basic Valve Body Options
Operating Temperature
Buna-N: 160°F (71°C) Maximum
EPDM: 300°F (140°C) Maximum
Viton™: 250°F (121°C) Maximum
Epoxy Coating**: 225°F (107°C) Maximum
** Valves can be provided without internal epoxy coating consult factory

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ES-A-ACV-LF920GD 2115 © 2021 Watts
Flow Data
Valve Travel
Valve Size - Inches 1¼ 1½22½ 3 4 6 8 10 12 14 16
Travel - Inches
3/8 3/8 1/2 5/8 3/4
11
1/2
22
1/2
33
1/2
4
Valve Cover Chamber Capacity
Valve Size - Inches 1¼ 1½22½ 3 4 6 8 10 12 14 16
fl.oz. 44410 16 22 70
U.S. Gal 1
1/4
2
1/2
46
1/2
9
1/2
Valve Size - Inches 1¼ 1½22½ 3 4 6 8 10 12 14 16
Maximum Continuous
Flow Rate Gpm (Water) 95 130 210 300 485 800 1850 3100 5000 7000 8500 11100
Maximum Intermittent
Flow Rate Gpm (Water) 119 161 265 390 590 1000 2300 4000 6250 8900 10800 14100
Minimum Flow Rate Gpm (Water) 3 5 6 9 15 16 17 25 55 70 190 400
CVFactor GPM (Globe) 26 26 48 75 112 188 387 764 1215 1734 2234 3131
CVFactor GPM (Angle) 26 27 57 91 125 207 571 889 1530 1945
Pressure Drop (psi)
2
3
4
6
8
10
20
30
40
60
80
100
Flow Rate - Gallons per minute (Water)
2410 20 40 60 80 100 200 500 1000 2000 5000 10000 20000 100000
8
6
4
8 10 12 14
16
6
2 1½ 1¼
2½
3
8 10 12
6
4
3
2½
2
1¼
1½
Angle
Globe
CVSuggested
• Maximum continuous flow based on velocity of 20 ft. per second.
• Maximum intermittent flow based on velocity of 25 ft. per second.
• Minimum flow rates based on a 20-40 psi pressure drop.
• The CvFactor of a value is the flow rate in US GPM at 60°F that will
cause a 1psi drop in pressure.
• Cvfactor can be used in the following equations to determine Flow
(Q) and Pressure Drop (∆P):
Q (Flow) = Cv√∆P ∆P (Pressure Drop) = (Q/Cv)2
• The Cv factors stated are based upon a fully open valve.
• Many factors should be considered in sizing control valves
including inlet pressure, outlet pressure and flow rates.
• For sizing questions including cavitation analysis consult Watts
with system details.
ACV Schematic - Series LF920GD

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ES-A-ACV-LF920GD 2115 © 2021 Watts
Basic Valve
Optional
Xylan
Coating
17A
6
1
2
3
4
5
7
8
9
11
12
13
14
15
16
17
18
10
Optional
Xylan
Coating
17A
6
1
2
3
4
5
7
8
9
11
12
13
14
15
16
17
18
10
Item Description Material
1Pipe Plug Lead Free Brass
2Cover ASTM A536 65-45-12 Epoxy Coated Ductile Iron
3Cover Bearing ASTM A276 304 Stainless Steel
4Stud with Cover Nut and Washer ASTM A570 Gr.33 Zinc Plated Steel
5Body ASTM A536 65-45-12 Epoxy Coated Ductile Iron
6Spring ASTM A276 302 Stainless Steel
7Stem Nut ASTM A276 304 Stainless Steel
8Lock Washer ASTM A276 304 Stainless Steel
9Stem Washer ASTM A276 304 Stainless Steel
10 Diaphragm Washer ASTM A536 65-45-12 Epoxy Coated Ductile Iron
11 Diaphragm* Buna-N (Nitrile)
12 Disc Retainer ASTM A536 65-45-12 Epoxy Coated Ductile Iron
13 Seat Disc* Buna-N (Nitrile)
14 Spacer Washer* x5 NY300 Fiber*
15 Disc Guide ASTM A743 CF8M (316) Stainless Steel
16 Shaft ASTM A276 304 Stainless Steel
17 Seat Ring** ASTM A743 CF8M (316) Stainless Steel
17A Seat Screw** (8" and Larger) ASTM A276 304 Stainless Steel
18 Seat Gasket* Buna-N (Nitrile)
* Contained in Main Valve Repair Kit
**Note: 6 inch and Smaller Valves, Seat Ring is threaded
Installation: If unit is installed in any orientation other than
horizontal (cover up) OR extreme space constraints exist,
consult customer service prior to or at the time of order.
NOTICE
ACV Schematic - Series LF920GD

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ES-A-ACV-LF920GD 2115 © 2021 Watts
Flanged and Threaded Grooved End
EE
A
B
C
E
F
D
Valve
Size
Globe Grooved Cover To Center Angle Grooved Angle Grooved Port Size
(npt)
Port Size
(npt)
Shipping Weights*
A B C D E F
in. in. mm in. mm in. mm in. mm in. in. lbs. kgs.
1

8

216 5

140 4

108 3

83
 ¼
25 11
1

8

216 5

140 4

108 3

83
 ¼
25 11
2 9 229 6

165 4

121 3

83
 
40 18
21⁄211 279 7

191 51⁄2140 4102
 
65 29
3121⁄2318 8

210 6152 4

108
 
95 43
415 381 10

270 7

191 5127
 
190 86
620 508 13

340
 
320 145
8253⁄8645 16 406 1 1 650 295
Grooved End Dimensions
Dimensions
Flanged and Threaded Dimensions
I
H
B
C
D
J
F
EG
K
L
K
A
K
Valve
Size
Globe Thread Globe 150# Globe 300# Cover To
Center
Angle Thread Angle 150# Angle 300# Angle Thread Angle 150# Angle 300# Port Size
NPT
Port Size
NPT
Shipping
Weights*
A B C D E F G H I J K L
in. in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. in. lbs. kgs.
1

7

184 5

140
 
20 9
1

7

184 8

216 5

140 3

83 1

48
 
25 11
29

238 9

238 10 254 6

171 4

120 4

121 5127 3

83 3

83 3

89
 
40 18
2

11 279 11 279 11

295 7

191 5

140 5

140 5

149 4102 4102 4

110
 
65 29
312

318 12 305 13

337 8

210 6

159 6152 6

162 4

114 4102 4

111
 
95 43
415 381 15

397 10

270 7

191 7

200 5127 5

135
 
190 86
620 508 21 533 13 330 10 254 10

267 6152 6

165
 
320 145
825

645 26

670 16 406 12

324 13

337 8203 8

216 1 1 650 295
10 29

756 31

791 17 430 14

378 15

395 8

219 9

237 1 1 940 426
12 34 864 35

902 20

530 17 432 17

451 13

349 14

368 11

1500 680
14 39 991 40

1029 24

616 11

1675 760
16 41

1051 43

1105 25

640 1 2 3100 1406
ACV Schematic - Series LF920GD

7
ES-A-ACV-LF920GD 2115 © 2021 Watts
LEAD FREE*
*The wetted surface of this product contacted by consumable water
contains less than 0.25% of lead by weight.
Model LFPV20C
Pressure Relief, Sustaining or
Backpressure Pilot
Size:
½
" NPT
The Model LFPV20C is a remote sensed direct acting, diaphragm
actuated Pilot that is used on various configurations of Automatic
Control Valves.
It is normally held closed by the force of the adjustable spring
setting above the diaphragm. It modulates toward an open posi-
tion when control pressure, exerting force below the diaphragm,
exceeds the spring setpoint, and modulates toward a closed
position when the control pressure falls below the spring setpoint.
The LFPV20C senses control pressure through a tapped port
below the diaphragm. The large diaphragm-to-seat ratio allows
it to open and close within tight pressure tolerances, accurately
positioning the Main Valve.
Turning the adjustment screw clockwise raises the control set-
point. Turning the adjustment screw counterclockwise lowers the
control setpoint.
The LFPV20C is equipped with one ½" NPT inlet and outlet port
and a ¼" NPT side sensing port located on the power chamber.
The ¼" side sensing port is used to monitor upstream or down-
stream pressure as required by specific valve function. Body Material: Lead Free Copper Silicon Alloy
Seat: 316 Stainless Steel
Elastomers: Buna-N (standard)
Viton™ (optional)
EPDM (optional)
Inlet Pressure Rating: 400psi (27.6 bar) maximum
Adjustment Rating: 20-200psi (1.4 - 13.8 bar) (standard)
0-30psi (0 - 2.1 bar) (optional)
100-300psi (6.9 - 20.7 bar) (optional)
200-450psi (13.8 - 31.0 bar) (optional)
Specifications
Model LFPV20C
Sense Port
Outlet
Inlet
1
2
3
4
5
7
9
10
11
8
6
12
13
14
16
17
18
19
20
21
15
17
7.30
1.00
3.50
Item Description
1Adjusting Screw
2Jam Nut
3Spring Housing
4Spring Guide
5Spring
6Cap Screw
7Power Chamber
8O-Ring*
9Body
10 Seat
11 O-Ring*
Item Description
12 Nut
13 Lockwasher
14 Diaphragm Washer
15 Diaphragm*
16 Diaphragm Washer
17 O-Ring*
18 Stem
19 Retainer
20 Rubber Disc*
21 Screw
*Included in Repair Kit
Viton™ is a trademark of The Chemours Company FC, LLC
ACV Standard Components - Series LF920GD

8
ES-A-ACV-LF920GD 2115 © 2021 Watts
LEAD FREE*
Model LFFC
Flow Control
Size:
½
" NPT
A Flow Control is an adjustable device used for tuning valve per-
formance. It can be installed to either control the opening or clos-
ing the speed of the automatic control main valve. When the flow
is in the direction of the needle the flow control is an adjustable
restriction. In the free flow direction the seat moves out of the flow
path to all unrestricted flow.
Specifications
Model LFFC
FLOW
CLOSED
Fluid Speed
Controlled by Needle
FLOW
OPEN
Free Flow
Seat Full Open
FLOW
CLOSED
Fluid Speed
Controlled by Needle
FLOW
OPEN
Free Flow
Seat Full Open
Size:
½" NPT
Body Material: Lead Free Brass
Stainless Steel (optional)
Seat: Lead Free Brass
Needle: Stainless Steel (304)
Elastomers: Buna-N (standard)
*The wetted surface of this product contacted by consumable water
contains less than 0.25% of lead by weight.
ACV Standard Components - Series LF920GD

9
ES-A-ACV-LF920GD 2115 © 2021 Watts
LEAD FREE*
Lead Free Ball Valve
Specifications
Standard Material: Copper Silicon Alloy Body and Adaptor
Chrome Plated Ball
Optional Material: Stainless Steel Housing, Body and Adaptor
Stainless Steel Ball
Pressure Rating: 600psi (41 bar) Non Shock
Temp Rating: -40°F - 400°F
C
H
L
Model BV
Ball Valve
Size:
¼
" – 1" NPT
Model BV Ball Valves are used in pilot lines to provide a positive
shutoff in any override or maintenance situation for simple trouble
shooting. This 2-piece, full port valve features: bottom loaded stems,
PTFE seats and packing.
Size Dimensions Weight
C H L
in. in. mm in. mm in. mm lbs. kg.
¼ 1 ⁄
46 3
⁄
87 1
¾ 45 0.4 0.2
⅜ 1 ⁄
46 3
⁄
87 1
¾ 45 0.4 0.2
½ 1 ⁄
46 3
⁄
87 1
⁄
50 0.4 0.2
¾ 2 ¼ 57 4101 2 ⁄
59 0.8 0.3
*The wetted surface of this product contacted by consumable water
contains less than 0.25% of lead by weight.
ACV Standard Components - Series LF920GD

ES-A-ACV-LF920GD 2115
10 © 2021 Watts
LEAD FREE*
Body Material: Lead Free Brass (standard)
Stainless Steel (optional)
Pressure Rating: 400psi (27.6 bar)
Filter Element: Monel
Screen Mesh: 40 Mesh (standard)
Specifications
B
A
Valve inlet with Filter installed
A B
Male Pipe Thread Female Pipe Thread
in. in.
¼ 1/8
3/8 ¼
½ 3/8
Model LF60
Flo-Clean Strainer
Size:
¼
" –
¾
" NPT
Model LF60 Flo-Clean Strainers are used to filter the fluid pass-
ing through the pilot circuit, and provide protection to pilot circuit
speed controls and pilots. It is installed in the inlet body port of
the Main Valve, exposing the strainer element to main line flow.
The currents and flow across the screen create a self-scouring
effect, cleaning the filter element.
*The wetted surface of this product contacted by consumable water
contains less than 0.25% of lead by weight.
Model LF60
ACV Options and Accessories - Series LF920GD