Hydro Test Procedures

HYDROSTATIC TEST

API 598

PROCEDURE MANUAL

Issued By : Kumaran QA

Approved By : Bernard Wong Managing Director

Date 18th Oct 2011 18th Oct 2011

Version 02

PANAFLO CONTROLS PTE LTD

HYDROSTATIC TEST API 598

DOC. NO PFC-QA-TP-01

REVISION 02

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1. Purpose

To define the retesting requirements for the metal seated Gate / Globe & Check valves and

Resilience seat Butterfly valve. Standard testing comprises hydrostatic testing of the pressure

envelope (body), backseat and seat tightness testing (hydrostatic and/or pneumatic) as

applicable.

2. RELEVANT STANDARD

The requirements set out in this standard are in accordance with the following International

Standards API 598,BS6755Pt.1, pr EN12266 Pt.1.The hydrostatic test pressures expressed in

this standard comply with ASME B16.34 for valves and API Std. 602 for Class 800 valves.

3. SCOPE

This specification applies to metal seated Gate / Globe & Check valves including bellows sealed

valves, tested according to API 598 Table 1 & 2 as described below. Valves specified for double

block & bleed are not covered by this procedure.

Test Description

NPS ≤ 4” & ASME Class ≤ 1500 NPS > 4” & ASME

Class ≤ 600

NPS ≤ 4” & ASME Class > 1500 NPS > 4” & ASME Class > 600

Gate Globe Check Gate Globe Check

Shell (Hydrostatic Body Test)

Required Required Required Required Required Required

Backseat (1) (Hydrostatic Seat

Test)

Required(4) Required(4) N/A Required(4) Required(4) N/A

High Pressure Closure (Hydrostatic

Seat Test)

Optional (2) Required (3) Required Required Required (3) Required

Low-pressure Closure (Pneumatic

Seat Test)

Required Optional (2) Optional (2) Optional (2) Optional (2) Optional (2)

(1) The backseat test is required for all valves, except bellows seal valves, that have the backseat

feature.

(2) When an optional test is specified by the purchaser, the test shall be performed in addition to

the required tests.




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(3) For power-operated and manually operated gear actuated globe valves, including non-return

type globe valves, the high-pressure closure test shall be performed at 110% of the design

differential pressure used for sizing of the operator.

(4) Unless stipulated otherwise by the purchaser, back seat test shall be the High-pressure

(hydrostatic) closure test.

4. TEST REQUIREMENTS

4.1. General

Surface treatments of pressure containing valve components to prevent corrosion during

storage prior to and during manufacture with a single primer coat (maximum 25 microns

thickness) or phosphate treatment is acceptable provided these preservations do not hide any

porosity.

4.2. Test Apparatus

Valves which have a split body design must not be tested on equipment which subjects the

valve to externally applied loads which may affect the body joint sealing performance. Single

piece bodied valves may be clamped.

4.3. Shell Test (Hydrostatic Body Test)

Every valve shall be subjected to a hydrostatic test of the body shell at 1.5 times the

maximum permissible working pressure at 100°F (38°C), see Table 1. The body should

remain tight for the test duration given in Table 1. The test shall show no leakage, no wetting

of the external surfaces, and no Permanent distortion under the full test pressure. No device

shall be used in testing the valve that will reduce the stress in the body.

The valve shall be set in the partially open position for this test, and completely filled with test

fluid. Any entrapped air should be vented from both ends and the body cavity via either

1) The upper test flange with the valve axis vertical.

2) The body vents connection with the valve axis horizontal. After venting the body, vent

plugs should be replaced.

The gland or bellows and anybody jointing shall be deemed as part of the pressure envelope.

Where a bellows is fitted, the stuffing box packing & gland shall not be fitted.

The valve shall then be brought to the required test pressure.




REVISION 02

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All external surfaces should be dried and the pressure held for at least the minimum test

duration. There shall be no visible leakage during the test duration specified in Table 2.

Note: For valves with adjustable stem seals, leakage through the stem seals during the shall

test shall not be cause for rejection, provided the stem seals are capable of retaining pressure

at least equal to the 100°F (38°C) valve rating without visible leakage.

If leakage is found, corrective action may be taken to eliminate the leakage and the test

repeated.

4.4. Backseat Test (Hydrostatic Seat Test)

When applicable (with exception of bellows seal valves), every valve shall be subjected to a

hydrostatic test of the backseat at 1.1 times the maximum permissible working pressure at

100° F (38°C), see Table 1. The seat sealing surface / closure Interface shall be free from oil,

grease and sealant. The backseat should remain tight for the test duration given in Table 1.

The test shall show no leakage, no wetting of the external surfaces, and no permanent

distortion under the full test pressure.

The valve shall be set in the fully open position with the packing gland loose or packing not

installed. If the backseat test is performed after the shell test, the packing shall be installed

and/or packing gland re-tightened after the backseat test.

The valve shall be completely filled with test fluid. Any entrapped air should be vented from

both ends and the body cavity via either

a) The upper test flange with the valve axis vertical or via the stem with the packing

removed.

b) The body vents connection with the valve axis horizontal. After venting the body,

vent plugs should be replaced.

The valve shall then be brought to the required test pressure.

All external surfaces should be dried and the pressure held for at least the minimum test

duration. There shall be no visible leakage during the test duration specified in Table 2.

If unacceptable leakage is found, corrective action may be taken to eliminate the leakage and

the test repeated. If the valve is disassembled to eliminate the leakage, all previous testing

must be repeated upon re-assembly.




REVISION 02

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4.5. High-pressure Closure Test (Hydrostatic Seat Test)

When applicable or specified by purchaser, every valve shall be subjected to a hydrostatic

seat test to 1.1 times the maximum permissible working pressure at 100° F (38°C), see Table

1 for the test duration specified in Table 1.

The seat sealing surface / closure interface shall be free from oil, grease and sealant.

Depending on the valve design and size a “varying settling in period” is allowed. The

allowable leakage of test fluid from the seat seal interface shall be according to those listed in

Table 2.

The test shall show no leakage through the disc, behind the seat rings or past the shaft seals.

With the valve in the partially open position, the cavity shall be completely filled with test fluid

and any entrapped air should be vented from both ends and the body cavity via either

a) The upper test flange with the valve axis vertical.

b) The body vents connection with the valve axis horizontal.

The valve should be closed and the body cavity vent (where fitted) shall remain open.

Gate Valve & Screw Down Non-return Globe Valve: The pressure shall be applied

successively to each side of the closed valve with the other side open to the atmosphere to

check for leakage at the atmospheric side of the closure.

Globe Valve: The pressure shall be applied in one direction with the pressure applied under

the disc (upstream side) of the closed valve with the other side open to the atmosphere to


Check valve: The pressure shall be applied in one direction with the pressure applied behind

the disc (downstream side) of the closed valve with the other side open to the atmosphere to


If unacceptable leakage is found, corrective action may be taken to eliminate the leakage and

the seat test repeated. If the valve is disassembled to eliminate the leakage, all previous

testing must be repeated upon re-assembly.




REVISION 02

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4.6. Low-pressure Closure Test (Pneumatic Seat Test)

When applicable or specified by purchaser, every valve shall be subjected to an air seat test

at a minimum gauge pressure differential of 4 to 7 bar (60-100 psig) for the test duration

specified in Table 1. The seat sealing surface / closure interface shall be free from oil, grease

and sealant. Depending on the valve design and size a “varying settling in period” is allowed.

The allowable leakage of test fluid from the seat seal interface shall be according to those

listed in Table 2. The test shall show no leakage through the disc, behind the seat rings or

past the shaft seals.

The valve should be moved to the half open position and any test fluid drained via either: -

a) The lower test flange with the valve axis vertical.

b) The body drains connection with the valve axis horizontal.

Gate Valve & Screw Down Non-return Globe Valve: The pressure shall be applied

successively to each side of the closed valve with the other side open to the atmosphere to


Globe Valve: The pressure shall be applied in one direction with the pressure applied under

the disc (upstream side) of the closed valve with the other side open to the atmosphere to


Check valve: The pressure shall be applied in one direction with the pressure applied behind

the disc (downstream side) of the closed valve with the other side open to the atmosphere to


5. TEST LIQUID

5.1. Test Liquid

Hydrostatic tests shall be carried out with water at ambient temperatures, within the range of

41°F (5°C) and 122°F (50°C), unless the use of another liquid is agreed between the

purchaser and the manufacturer. If water is used, it will contain water-soluble oil or rust

Inhibitor. Potable water used for pressure test of austenitic stainless steel valves shall have

chloride content less than 30ppm and for carbon steel valves shall be less than 200ppm.




REVISION 02

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5.2. Cleaning

Austenitic and duplex stainless steel valves and valves made of 9% nickel alloy shall be

flushed with demineralized water (chloride content of 1ppm maximum) immediately after the

hydrostatic test.

5.3. Drying

After Hydrostatic testing, the valves should be blown through using dry compressed air,

followed by a visual inspection for dryness. If moisture is still found, the above process shall

be repeated until visually dry.

6. TEST GAUGES

Test bay gauges shall be calibrated at once a year.

7. TEST CERTIFICATION

According to attached model test certificate confirming that the valves have been tested in

accordance with the requirements of this specification.

Table 1 Test Pressure & Time duration

Class 150# 300#

Description

Material

CWP Shell Seat CWP Shell Seat

psig Kg/cm2 Kg/cm2

psig Kg/cm2 Kg/cm2

A105, A350-LF2,

A216WCB, A352 LCC 285 32 23 740 80 59

A182-F5,F9,F11,F22 290 32 23 750 80 59

A182-F304,F316 275 30 23 720 78 57

A182-F304L, F316L 230 25 20 600 64 48

Class 600# 800#

Description

Material


psig Kg/cm2 Kg/cm2

psig Kg/cm2 Kg/cm2

A105, A350-LF2

A216WCB, A352 LCC 1480 157 117 1975 210 153

A182-F5,F9,F11,F22 1500 159 117 2000 211 155

A182-F304,F316 1440 153 113 1920 204 150

A182-F304L, F316L 1200 127 94 1600 169 125




REVISION 02

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Class 900# 1500#

Description Material


psig Kg/cm2 Kg/cm2

psig Kg/cm2 Kg/cm2

A105, A350-LF2

A216WCB, A352 LCC 2225 235 173 3705 392 289

A182-F5,F9,F11,F22 2250 233 172 3750 396 291

A182-F304,F316 2160 224 164 3600 380 280

A182-F304L, F316L 1800 187 137 3000 317 233

Class 2500# -

Description

Material


psig Kg/cm2 Kg/cm2

psig Kg/cm2 Kg/cm2

A105, A350-LF2 A216WCB, A352 LCC

6170 653 478 - - -

A182-F5,F9,F11,F22 6250 660 484 - - -

A182-F304,F316 6000 633 465 - - -

A182-F304L, F316L 5000 528 387 - - -

CWP: The maximum allowable pressure at –20 OF to 100 OF 38°C).

TABLE 2 – TEST DURATION

NOMINAL

SIZE (NPS) MINIMUM TEST DURATIONS (Seconds)

Hydro Shell Test Backseat Test Hydro Seat Test Air Seat Test

≤ 2” 15 15 15 15

2 1/2” – 6” 60 60 60 60

8” – 12” 120 60 120 120

≥ 14” 300 60 120 120




REVISION 02

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Table 2 Maximum Allowable Leakage for Seat Test

Valve Size All

Resilient

Seated

Valves

Metal Seated Valves

Except Check Metal Seated Check valves

DN

(mm)

NPS

(in.)

Liquid Test

(drops/minute)

Gas Test

(bubbles/minut

e)

Liquid

Test

(cc/min)

Gas Test

(m3/h)

Gas Test

(ft3/h)

< 50 < 2 0 0 0 6 0.08 3

65 2 1/2 0 5 10 7.5 0.11 3.75

80 3 0 6 12 9 0.13 4.5

100 4 0 8 16 12 0.17 6

125 5 0 10 20 15 0.21 7.5

150 6 0 12 24 18 0.25 9

200 8 0 16 32 24 0.34 12

250 10 0 20 40 30 0.42 15

300 12 0 24 48 36 0.50 18

350 14 0 28 56 42 0.59 21

400 16 0 32 64 48 0.67 24

450 18 0 36 72 54 0.76 27

500 20 0 40 80 60 0.84 30

600 24 0 48 96 72 1.01 36

650 26 0 52 104 78 1.09 39

700 28 0 56 112 84 1.18 42

750 30 0 60 120 90 1.26 45

800 32 0 64 128 96 1.34 48

900 36 0 72 114 108 1.51 54

1000 40 0 80 160 120 1.68 60

1050 42 0 84 168 126 1.76 63

1200 48 0 96 192 144 2.02 72




REVISION 02

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a For the Liquid test, 1 ml is considered equivalent to 16 drops.

b

There shall be no leakage for minimum specified test duration (see table 2). For Liquid

test, 0 drops means no visible leakage per minimum specified test duration.

For gas test, 0 bubbles means less than 1 bubble per minimum specified test duration.

Hydro Test Procedures

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