Automatic Shut-off Valves

CanGaSys.    SSV SERIES

              

INTRODUCTION

 

CanGaSys SSV series Automatic Shutoff Valves are used for the control of liquid or gaseous fuels and gases. They have been sold thousands of sets to be installed into gas distribution systems, factories, hospitals, schools and public buildings; they have served for years with highly safety and satisfaction of customer. These Automatic Security Shutoff Valves are the finest but simple maintenance designed and most complete product line of such devices available in the world today. The valves are produced to perform a particular function in gas distribution, and are not additional model or modified, reworked versions of some existing regulators. CanGaSys SSV series are available in a complete range of sizes from 1กจ through 8กจ in a variety of models and designs, and are suitable for use on shut-off pressures ranging from inches water column to 56 bars. They van be installed either upstream or downstream of a regulator or meter, and may be acting directly by sensing line from pipeline or by a remote pressure source by means of an external control line.

APPLICATION

The CanGaSys SSV series are slaved as the main safety device for transmission, distribution; measurement of natural gas or LPG gas system protection, and also applicable in pressure regulating systems of industrial and commercial installations, for non-corrosive gas systems in general.

 

CONSTRUCTION

The design concept of the automatic security shutoff is a hinged door closing onto a knife-edged seat fully contained in a high-grade ductile iron body (or steel casting). Normally in the open position the release mechanism is housed within a separate trigger chamber with inspection port. All internals have been selected for their anti-corrosion properties; include chromium plated mild steel, brass and stainless steel parts.

 

A specially designed spindle and seal between the trigger mechanism and the diaphragm actuator ensures positive operation and virtually eliminates the effect of inlet pressure variation on the cut-off pressure set point. The actuator normally is a nitrite synthetic rubber diaphragm with nylon reinforcement.  Thinner diaphragms for achieving maximum sensitivity are used in low-pressure cut-off models.  The valve also features an integral ¼กจ ball valve for pressure equalizing, to eliminate the need of a separate bypass and a viton synthetic rubber door seating to ensure the suitability of the valve for a wide range of distributed gases.

OPERATION PRINCIPLE

The CanGaSys SSV series Valves are safety devices designed to stop the flow of gas when the downstream pressure of the valve or pipeline reaches a value larger than and/or smaller than the preset pressure point. The valve remains open when the operating pressure is in the normal operating range. If the valve actuates or is triggered on (either due to overpressure or under pressure) the valve will remain closed until a technician or mechanic visits the site, and verifies installation integrity. The valve can only be reset (re-opened) after the installation operating pressure returns to the normal range.

 

CanGaSys SSV series (SSV-IH & SSV-IL)

  Models SSV-IH & SSV-IL are designed to close automatically in the case of an overpressure condition occurred. The valves are externally controlled shutoff valves requiring an external control sensing line. Control pressure is transmitted through the external control line from down stream to the diaphragm chamber of SSV. The valves are normally installed upstream of the regulator or pressure control point, with the external control line installed approximately eight pipe diameters downstream of the regulator. When the external control pressure increases to the shutoff pressure setting point of the valve, the external control pressure acting on the underside of the diaphragm, which breaks the balance of the compression of the pressure spring and the latch lever, triggers the latch and disengages valve disc arm from the latch.  When this occurs, the valve disc moves to the closed position aided by the resetting shaft spring and line pressure, cutting the gas flow. After slam shutting, the valve must be reset to the open position manually, by normal external control pressure being restored. To reset (open) the disc it is necessary to open the by-pass valve, which will equalize the pressure upstream and downstream of the valve disc.

 

Model SSV-IL is serviced in low-pressure applications, where the shutoff pressure settings do not exceed 3 psig.

 

Model SSV-IH is serviced in high-pressure applications, where the shutoff pressure settings are above 3 psig.

  

CanGaSys SSV series (SSV-DH & SSV-DL)

 Models SSV-DH & SSV-DL are designed to close automatically in the event of an under pressure condition occurred. The valves are externally controlled shutoff valves requiring an external control sensing line.  Control pressure is transmitted through the external control line from down stream to the diaphragm chamber.  of SSV. The valves are normally installed upstream of the regulator or pressure control point, with the external control line installed approximately eight pipe diameters downstream of the regulator. When the external control pressure decreases to the shutoff pressure setting of the valve, the compression of the pressure spring forces the diaphragm and attached stem downward and the latch disengages from the valve disc arm.  When this occurs, the valve disc moves to the closed position aided by the resetting shaft spring, cutting the gas flow.  After slam shutting, the valve must be reset to the open position manually, by normal external control pressure being restored. To reset (open) the disc it is necessary to open the by-pass valve, which will equalize the pressure upstream and downstream of the valve disc.

 

Model SSV-DL is serviced in low-pressure applications, where the shutoff pressure settings do not exceed 3 psig.

 

Model SSV-DH is serviced in high-pressure applications, where the shutoff pressure settings are above 3 psig.

 

TECHNICAL CHARACTERISTICS

Component

Material

Body

Carbon Steel - ASTM A216 Gr. WCB
Nodular Iron  - ASTM A 536 Gr.60.45.12

Shaft

Stainless Steel

Shutter

Brass / Stainless Steel / Polyurethane

Seat

Brass / Stainless Steel /

Elastometers

Buna-N /  Viton /  EPDM

 

Nominal Diameter

Connection

1"

NPT Thread ANSI B2.1 / 
Flanges according to ANSI B.16.5, Classes 150#RF, 300#RF and 600#RF, or RTJ

2"

Flanges according to ANSI B.16.5, Classes 150#RF, 300#RF and 600#RF, or RTJ

3"

4"

6"

8"

 

Maximum Operating Pressures

MATERIAL 

#150

#300

#600

Carbon Steel

19.7 bar

51 bar

102 bar

Nodular Iron

18 bar

45 bar

--

            Note : from 0ºC to 38ºC  (According to ANSI B16.5A-1998)

 

 

Model

Function

Operation Range

GIPS-L

Over pressure Blocking

Low Pressure

(20 mbar to 260 mbar)

GDPS-L

Under pressure Blocking

GIPS-H

Over pressure Blocking

Medium Pressure
(0.2 bar to 16 bar)

GDPS-H

Under pressure Blocking

GIPS-PH

Over pressure Blocking

High Pressure

(12.2 bar to 56 bar)

GDPS-PH

Under pressure Blocking

GIDPS-H

Over pressure and Under pressure Blocking

0.2 bar to 16 bar

 for Decreasing

12.2 bar to 56 bar

for Increasing

GIDPS-PH

Over pressure and Under pressure Blocking

 

Pressure Range

Precision (DIN 3381)

%

.02 - .16 bar

AG 10 / 10%

.15 - .5 bar

AG 5 / 5%

.3 - 16 bar

AG 2.5 / 2.5%

15 - 55 bar

AG 1 / 1%

                        Note: Operation Time < 2 seconds

GIPS and GDPS Setting Spring Ranges

CODE

SPRING COLOR

RANGE

APPLICATION

NOMINAL DIA.

01.49.23

Green

20 - 50 mbar

GIPS-L & GDPS-L

1", 2", 3" & 4"

01.49.25

Black

45 - 160 mbar

GIPS-L & GDPS-L

01.49.49

White

150 - 260 mbar

GIPS-L & GDPS-L

01.49.11

Blue

.2 - .5 bar

GIPS-H & GDPS-H

01.49.10

Green

.3 - 1.5 bar

GIPS-H & GDPS-H

01.49.09

Brown

1.0 - 4.0 bar

GDPS-H

01.49.09

Brown

1.0 - 5.0 bar

GIPS-H

01.49.08

Black

4.2 - 10.2 bar

GIPS-H & GDPS-H

01.49.12

Yellow

2.0 - 16.0 bar

GIPS-H & GDPS-H

01.49.08

Black

12.2 - 20.4 bar

GIPS-PH & GDPS-PH

01.49.12

Yellow

18.4 - 31.7 bar

GIPS-PH & GDPS-PH

01.49.07

Silver

30.6 - 56 bar

GIPS-PH & GDPS-PH

01.49.10

Green

.3 - 1.3 bar

GIPS-H

6" & 8"

01.49.09

Brown

.6 - 3.6 bar

GIPS-H

01.49.08

Black

.8 - 7.7 bar

GIPS-H & GIPS-PH

01.49.12

Yellow

1.5 - 16.5 bar

GIPS-H & GIPS-PH

01.49.07

Silver

2.4 - 16.5 bar

GiPS-H & GiPS-PH

01.49.10

Green

.8 - 1.8 bar

GDPS-H

01.49.09

Brown

1.0 - 3.6 bar

GDPS-H

01.49.08

Black

1.5 - 7.0 bar

GDPS-H & GDPS-PH

01.49.12

Yellow

1.5 - 12 bar

GDPS-H & GDPS-PH

01.49.07

Silver

2.4 - 16.5 bar

GDPS-H & GDPS-PH

 

 

GIDPS Setting Spring Ranges (with HI-LO Pilot)

Spring Range for Pressure Increasing

CODE

SPRING COLOR

H Model

PH Model

01.49.11

Blue

.2 - .4 bar

---

01.49.10

Green

.3 - 1.5 bar

---

01.49.09

Brown

1.0 - 5.5 bar

---

01.49.08

Black

4.2 - 9.2 bar

12.2 - 20.4 bar

01.49.12

Yellow

8.0 - 16.0 bar

18.4 - 31.7 bar

01.49.07

Silver

---

30.6 - 56 bar

 

Spring Range for Pressure Decreasing

CODE

SPRING COLOR

H Model

PH Model

01.49.10

Green

.2 - 1.5 bar

---

01.49.09

Brown

1.0 - 5.0 bar

---

01.49.08

Black

4.2 - 9.2 bar

12 - 19 bar

01.49.12

Yellow

8.0 - 15.0 bar

18 - 31 bar

01.49.07

Silver

---

30.6 - 55 bar

    NOTE: The GIDPS valve model, beside the Hi-Lo pilots springs, has a spring used only for loading assembled at main diaphragm upper side, which changes according to the desired operating conditions:

  

 

Loading Springs

NOMINAL DIAMETER

CODE

SPRING COLOR

Maximum Input

 (bar)

1" -  4"

01.49.43

Chromed

10

01.50.97

Black/Orange

48

01.49.11

Blue

90

6" -  8"

01.50.97

Black/Orange

20

01.50.21

White

50

01.51.09

Black

90

 

 

 

Dimensions (mm) & Weights

A

B

C

D

E

Weight (kg)

 

#150

#300

#600

#150

#300

#600

#150

#300

#600 RF

#600 RTJ

#150

#300

#600

#150

#300

#600

#150

#300

#600

GIPS-L/GDPS-L

1"

108

124

277

283

163

182

167

---

5.6

7.4

9

2"

152

165

190

211

214

10

12

15

3"

190

210

333

335

283

283

25

27

34

4"

229

254

273

338

345

304

317

320

170

41

45

59

GIPS-H/GDPS-H

1"

108

124

277

283

163

182

92

---

5.6

7.4

9

2"

152

165

190

211

214

10

12

15

3"

190

210

333

335

283

283

153

25

27

34

4"

229

254

273

338

345

304

317

320

168

41

45

59

6"

279

318

356

395

395

470

505

508

356

107

125

169

8"

343

381

419

461

486

543

568

610

613

440

157

184

248

GIPS-PH/GDPS-PH

1"

108

124

277

283

163

182

92

---

5.6

7.4

9

2"

152

165

190

211

214

10

12

15

3"

190

210

333

335

283

283

153

25

27

34

4"

229

254

273

338

345

304

317

320

168

41

45

59

6"

279

318

356

395

395

470

505

508

356

107

125

169

8"

343

381

419

461

486

543

568

610

613

440

157

184

248

GIDPS-HiLo

1"

108

124

194

200

163

182

92

207

8.6

10.4

12

2"

152

165

204

190

211

214

13

15

18

3"

190

210

237

297

283

283

153

28

30

37

4"

229

254

273

244

281

304

317

320

168

44

48

62

6"

279

318

356

342

470

505

508

356

260

110

128

172

8"

343

381

419

461

486

543

568

610

613

440

157

184

248

Valves' Head Loss Calculation (Dp)

 

 

Nominal Diameter

Flow Coefficient (K)

Where:
Dp = p1 - p2 (bar)
Q = Gas Flow (Sm3/hr)
P1 = Valve upstream pressure (bar abs)
P2 = Valve downstream pressure (bar abs)
K - Valve flow coefficient

(see table)

 

1"

451

2"

3050

 

3"

9640

 

4"

18450

 

6"

45130

 

8"

71800