Quality

Quality & Inspection 

All CONNEX Valves are inspected and tested at the factory as per procedures, that are in strict compliance with API and DIN/EN Specifications.


Inspections and Testing of CNX Cast Steel Valves are done as below.

1. Visual Examination

2. Hydrostatic shell test.

3. Backseat test.

4. Seat (water) test.

5. Low pressure (air) test.


CONNEX Cast Steel Valves are inspected and tested in detail as follows.

1. VISUAL EXAMINATION:

(Gate, Globe, Ball, Butterfly, Strainer and Swing Check Valves)

A visual examination is performed on all casting of bodies, bonnets, covers and closure elements in accordance with MSS-SP-55, Quality Standards for Steel. Castings and with reference to purchase specifications.


2. HYDROSTATIC SHELL TEST:

(Gate, Globe, Ball, Butterfly, Strainer and Swing Check Valve)

The purpose of this test is to ensure that the valve shell will withstand pressures up to 1.5 times of the working pressure at the 100°F for Body & 1.1 times for seat rating with no visual leakage or harmful in elastic deformation.

a) Frequency of Hydrostatic Shell Test

100% on all bodies.

b) Test Media

The test media is water containing a rust inhibitor at a temperature not exceeding 100 °F.

c) Test Pressure

The shell test pressure is 1.5 time of the design or working pressure rating of the valve, as per the standards.

VALVE RATING

TEST PRESSURE (PSIG)

Class 150

450

Class 300

1125

Class 600 (WCB)

2225

Class 600 (Other than WCB)

2250

 

d) Test Duration

VALVE NPS

MIN. TEST DURATION (SEC)

≤2

15

2-1/2”-6”

60

8”-12”

120

14” & ABOVE

300


e) Test Procedures

The shell test is performed by partially opening the valve assuring that all internal surfaces seals and packing are exposed to the test media and apply pressure for the suitable time duration.

f) Acceptance / Rejection-criteria

No visible evidence of external leakage for the duration of the test.


3. BACKSEAT TEST

(Gate and Globe Valves only)

The purpose of the backseat test is to ensure that the stem backseat area will not leak at 1.1 times the pressure rating.

a) Frequency of Backseat Test

100% on all Gate and Globe Valves.

b) Test Media

The test media is water containing a rust inhibitor at a indoor temperature 0 - 25 ℃.


4. SEAT TEST (WATER)

(Gate, Globe, Ball, Butterfly and Swing Check Valves)

The purpose of the seat test is to ensure that the sealing area will not leak at 1.1 times the pressure rating.

a)  Frequency of seat Test

100% on all shuf-off valves (Gate, Globe, Ball, Butterfly and Swing Check Valves)

b)  Test Media

The test media is water containing a rust inhibitor at a indoor temperature 0 - 25 ℃.

c) Test Pressure

The seat test pressure is 1.1 time of the design or working pressure rating of the valve, as per the standards.

VALVE RATING

TEST PRESSURE (bar)

Class 150

22

Class 300

55

Class 600 

110

Class 900 

165

Class 1500 

275

d) Test Duration

VALVE NPS

MIN. TEST DURATION (SEC)

≤2

15

2-1/2”-6”

60

8”-12”

120

14” & LARGER

300

e) Test Procedures

The seat test is performed by completely closed the valve, the water is fully in the upstream port, then check the sealing area on downstream side. For the bi-directional valves, the test shall be performed again from the other side.

f) Acceptance / Rejection-criteria

No visible evidence of leakage for the duration of the test.


5. LOW PRESSURE (AIR) TEST 

(Gate, Globe, Ball, Butterfly)

The purpose of the low pressure test is to ensure that the sealing area will not leak at 0.6 MPa (6 bar) air pressure.

a) Acceptance / Rejection-criteria

No bubble for the duration of the test.