Hydrotest Blind

Pressure testing Piping and equipment at construction sites

LINDE STANDARD

LS 133-02

Page 1 of 9

Remarks on the current issue:

Revision: Blind thicknesses in annex C changed; editorially revised. Previous issues: 05.2006, 07.2006, 07.2008 Responsible department(s) for the technical content: GCQ Confidentiality class 1 in accordance with LS 104-03: Unrestricted publication

X 06 01.2013 GCQ / Henn GCQ / Helmreich LEHQ-ENM1S / Schmitt X 05 07.2008 TM-Q / Henn TAW / Rahofer TAW-N / Schmitt

Status Issue Date Prepared Checked Approved Linde AG File name: LS 133-02 (EN)

Contents

1 Scope ................................................................ 22 Scheduling of the pressure test......................... 23 Test method ...................................................... 24 Requirements .................................................... 25 Performance ...................................................... 35.1 Hydrostatic test ................................................. 35.2 Pneumatic test .................................................. 46 Water quality ..................................................... 47 Exceptional cases ............................................. 58 Test results and test report ............................... 5 Annex A (normative) Performance of

pneumatic testing .................................... 6Annex B (normative) Safety areas for

pneumatic testing .................................... 7Annex C (normative) Temporary blinds for

pressure testing ...................................... 8

Linde AG, Engineering Division Issue 06/01.2013 LS 133-02 Page 2 of 9

Linde AG File name: LS 133-02 (EN)

1 Scope This standard applies to the performance of pressure tests, i. e. hydrostatic or pneumatic tests of piping and equipment on construction sites or pre-fabrication sites.

During pressure testing the leak tightness, the form/shape stability and the strength integrity of the test system will be determined.

Project specific or component specific requirements from codes, regulations or specifications have preference over the requirements of this standard.

2 Scheduling of the pressure test Pressure testing shall be performed after completion of construction activities on the pressure-retaining wall and after inspection and release by the inspection agency, but prior to applying painting, insulation, rubber coating, brick-lining, metallic liners and similar coating to the inside and outside wall.

For piping a single-layer outside primer is admissible, provided that the consents of the purchaser, authority resp. inspection agency exists.

For underground piping the area of the welding seams shall be accessible for inspection.

During the pressure test the number of personnel in the direct neighborhood shall be limited to a minimum (e.g. testing after working hours).

3 Test method The standard test method is hydrostatic testing, by using water as test fluid. The additional static load due to the water weight of the systems to be tested, to supports, foundations, etc. shall be considered by taking appropriate measures.

If in exceptional cases e.g. due to process reasons, the hydrostatic test is not suitable the pressure test may be performed as pneumatic test, after consultation with the purchaser. Due to the risk potential occurring with compressed gases precautions shall be taken for personnel protection. If applicable, the test shall be previously agreed upon with the relevant industrial safety authorities and the inspection agency.

Generally, pressure testing shall be performed at room / ambient temperature. At low ambient temperature (< 5 C), additional measures shall be agreed upon with the purchaser and the inspection agency.

If pressure vessels are subject to pressure testing on site, the instructions of the vessel manufacturer shall be observed.

NOTE: Heat exchangers can be designed for differential pressure. This shall be considered during pressure testing. Corresponding data are shown on the vessel nameplate.

4 Requirements For pressure testing the following minimum requirements shall apply:

If components with longitudinal welds are installed, these welds shall be prior pressure-tested or 100% nondestructively tested (shall apply to pneumatic test only)

Parts which are to be excluded from the pressure test (e.g. rupture discs, sensitive measuring instruments, special components subject to a lower test pressure) shall be dismantled or isolated from the system.

Documents specifying test method (test fluid), pressure test limits and test pressure shall be prior approved by purchaser. (e.g. drawings with welding and testing plan or line/isometric list, isometric drawing with defined pressure test circuits, etc.)

The static pressure of the water column shall be considered at large differences in height Advance notice for inspection to the parties involved shall be given. Pre-condition for pressure testing are the accepted final inspection and compliance with specified scope

of examinations



For pneumatic testing, radiographic examination of at least 10 % of all circumferential-welds and nozzle welds > DN 100 (4 inches) shall be required. Nozzle welds which cannot be radiographed shall where appropriate be ultrasonically tested resp. tested for surface cracks

Calibrated measuring instruments (pressure gauge, pressure transmitter) with measuring range < 1.5 x test pressure shall be used; for pneumatic testing 2 independent measuring instruments with remote reading or with reading from a protected area will be required, preferably with pressure recorder

Safety measures shall be observed against unintentional pressure increase due to heating of the test fluid at rising ambient temperature. The pump shall be separated from the test system during testing

Sufficiently dimensioned parts for isolating the pressure chamber, such as blind flanges, line blinds, caps, pressure devices (for temporary blinds refer to Annex C) shall be used

For hydrostatic testing the installation of vents and drains at high and low points will be required Safety distances for test personnel and other involved persons according to Annex B for pneumatic

testing shall be observed

Pneumatic testing systems shall be kept small and large-size vessels shall be isolated, if possible. Demarcation of a separate protection area and marking with "no access permitted" will be required

A responsible for supervision of the defined safety precautions and performance of the pressure testing shall be nominated

Approval for the pneumatic testing by the authority and the purchaser shall be obtained

5 Performance Test pressures and performance shall be acc. to the specified codes and standards.

NOTE: The factor for the calculation of the test pressure is not always constant. Calculated stress factors for the design temperature (temperature correction factor) as specified in design and construction codes may have to be considered.

5.1 Hydrostatic test The test fluid shall be water according to Paragraph 6; the test pressure shall be applied at the

highest point

Securing of a dry outside surface (e.g. protection against rainy weather); in case of condensate, waiting for temperature balance between test fluid and wall

Piping spring hangers shall be locked. Safety distance for pressure vessels shall be at least 1 x vessel length Pressure chamber shall be completely vented during filling Temperature control; pressurization only after reaching of the specified test temperature (= metal

temperature)

The pressure shall be increased slowly and continuously till reaching test pressure. Minimum holding period at test pressure shall be observed. Visual examination of the walls after 15 min at the earliest and for piping with covered welds (under

reinforcing pads, etc.) after at least 30 min holding time at test pressure

Visual examination for leaks of the welds and detachable connections Prior to draining: open vents, otherwise danger of bulging due to forming vacuum After pressure testing immediate draining of water, removal of water residues, if any (e.g. by blowing) and

venting of the walls, otherwise danger of corrosion

Removal of deposits (rust, mud); flushing of the piping, if required



5.2 Pneumatic test The test fluid shall be an oil-free and dry gas, air or nitrogen Observation of safety precautions Pressurization and pressure verification from a safe distance see Annex A and B First leak test at 0.5 to 1.0 bar by visual examination of the welds and detachable connections after

application of foam-frothing agent

Increase pressure slowly and step-by-step till reaching test pressure; after a holding period of 10 min each, visual examination and noise control from a safe distance

At test pressure (acc. Code) a holding time of at least 30 min (no access permitted during holding time above max. allowable working pressure!)

If a safety valve is installed for protection against unintentional pressure increase (e.g. acc. to ASME B31.3), the cross-section of the safety valve shall consider the required blow off volume

Access to the safety area only after decrease of the test pressure to the maximum allowable working pressure. At this pressure inspect the piping for deformations and cracks. In the welding seam zone and on all detachable connections a second leak test with frothing agents (bubble test) shall be performed additionally

Exemption for Cold Boxes: Due to safety precautions the leak test on welds at maximum allowable working pressure, with foam-frothing agents, shall be omitted. This leak test shall be carried out after pressure release to 0.5 1.0 bar

Continuous decrease of pressure; venting the pressure chamber of vessels and piping, which had been tested with nitrogen, otherwise risk of suffocation during access

Washing off of the residues of the foam-frothing agent to prevent corrosion

6 Water quality For the pressure test with liquid, clean (free from suspended substances) water of drinking water quality shall be used. The admissible chloride content (including bromides, iodides) is specified in Table 1. The material data given in Table 1 shall apply to all surfaces being in contact with water, i.e. also to metallic internals and claddings. For constructions involving material combinations, the more stringent requirements each shall apply.

Table 1: Admissible chloride content of the water for pressure testing

Material group Chloride content ppm = mg/l 1 Ferritic steels, unalloyed/low-alloyed steels 9% Cr,

welded with ferritic filler material < 250

2 Ferritic-austenitic steels, Mo-alloyed (duplex steels) < 150 3 Stainless 18/9-CrNi-steels, Mo-alloyed

4 Aluminium materials 5 Stainless 18/9-CrNi-steels without Mo

< 50 6 Stainless, ferritic Cr-steels 7 Ferritic steels, welded with austenitic filler material 8 Heat-resistant, austenitic steels (CrNi, NiCr) and Ni-base alloys9 Copper materials including brass no

limitation 10 Plastic materials



7 Exceptional cases If, in exceptional cases, water is to be used with a chloride content exceeding the values of Table 1, namely

up to max. 500 ppm for the material groups 1 to 3 up to max. 150 ppm for the material groups 4 to 8 it shall be inhibited, e.g. with 1.5 % by weight of sodium carbonate or 0.5 % by weight of sodium nitrate. Inhibition with lime solution or organic inhibitors needs the consent of the purchaser. For inhibition and additions to water for obtaining a freezing point depression the local applicable regulations for water shall be observed.

At unknown or considerably variable water quality, the determination of the halides (chloride, bromide, iodide) is required prior to each pressure testing, e.g. by means of "Aquaquant Chlorid" from Merck, Darmstadt.

If the proceeding acc. to this standard is not useful for an individual case, the details shall be agreed upon with the purchaser and the inspection agency, e.g. for

ambient temperatures below 5 C, using another liquid instead of water, using another gas instead of air or nitrogen, plastic components, e.g. GRP.

8 Test results and test report The requirements are fulfilled, if

no inadmissible pressure drop is recorded and no inadmissible deformations are found and no liquid penetrates to the surface during the hydrostatic test or no formation of foam is detected during the pneumatic test The accepted pressure test shall be confirmed in a test report by the parties involved, by observing the specified regulations, and by indicating the equipment tested, test method, test pressure, test period, test fluid, test results and date and, where applicable, test temperature, pressure gauge No. with calibration certificate and pressure recorder report.

At a not accepted pressure test, the purchaser shall be informed immediately. The further proceeding shall then be agreed upon with the purchaser and the parties involved.



Annex A (normative)

Performance of pneumatic testing

D

SG

SG

SG

SG

SG

SG

SG

D

0.5p

0.6p

0.7p

0.8p

0.9p

1.0p

Pt

0.5-1.0 bar

0

t t

0

D*)

Start End

Pre

ssur

e

Time

h

Figure A.1: Performance of a pneumatic test Pt Test pressure (acc. Code) t Holding time 10 min th Holding time 30 min D Leak test with foam-frothing agent according Paragraph 5.2 SG Visual examination and noise control *) applies for cold boxes in lieu of leak testing at 1.0 p



Annex B (normative)

Safety areas for pneumatic testing

For pressure vessels the safety distance shall be according Table B.1.

For piping the safety distance shall be in accordance with Table B.1 and upon consultation with the parties involved.

Table B.1: Safety distances for vessels

Safety Distance m

Volume m3

Pt=5 bar

Pt=10 bar

Pt=15 bar

Pt=20 bar

Pt=25 bar

Pt=30 bar

Pt=35 bar

Pt=40 bar

1 2.1 3,3 4.3 5.1 5.9 6.5 7.1 7.72 2.9 4.7 6.1 7.2 8.3 9.2 10.1 10.9 3 3.6 5.7 7.4 8.9 10.1 11.3 12.4 13.4 4 4.1 6.6 8.6 10.2 11.7 13.0 14.3 15.4 5 4.6 7.4 9.6 11.5 13.1 14.6 16.0 17.2 7 5.4 8.8 11.4 13.6 15.5 17.3 18.9 20.4 10 6.5 10.5 13.6 16.2 18.5 20.6 22.6 24.4 15 7.9 12.8 16.6 19.8 22.7 25.3 27.6 29.9 20 9.2 14.8 19.2 22.9 26.2 29.2 31.9 34.5 30 11.2 18.2 23.5 28.1 32.1 35.7 39.1 42.2 40 13.0 21.0 27.2 32.4 37.0 41.3 45.1 48.8 50 14.5 23.5 30.4 36.2 41.4 46.1 50.5 54.5 60 15.9 25.7 33.3 39.7 45.4 50.5 55.3 59.7 70 17.2 27.7 35.9 42.9 49.0 54.6 59.7 64.5 80 18.3 29.7 38.4 45.8 52.4 58.3 63.8 69.0 90 19.5 31.5 40.7 48.6 55.6 61.9 67.7 73.1 100 20.5 33.2 42.9 51.2 58.6 65.2 71.4 77.1 150 25.1 40.6 52.6 62.7 71.7 79.9 87.4 94.4 200 29.0 46.9 60.7 72.4 82.8 92.2 100.9 109.0 300 35.5 57.4 74.4 88.7 101.4 113.0 123.6 133.5 400 41.0 66.3 85.9 102.5 117.1 130.5 142.7 154.2 500 45.9 74.2 96.0 114.5 131.0 145.8 159.6 172.4 Note: The values shown in the table are based on the following formula acc. to Regels voor toestellen onder druk "Rules for pressure vessels" T 0240:

714.051.1 tt ppVl in which: l = safety distance V = volume pt = test pressure Intermediate values can be interpolated.



Annex C (normative)

Temporary blinds for pressure testing

C.1 General requirements Temporary blinds shall always be installed between a pair of flanges.

Table C.1 defines the minimum thickness of temporary blinds to be used for the purpose of pressure testing only. These thicknesses are calculated considering a minimum yield strength of 235 MPa of the material at room / ambient temperature. In case materials are used with deviating applicable calculation strength values, a calculation for the thickness shall be provided to the purchaser prior to pressure testing.

Temporary blinds shall not be used as blind flanges resp. line blinds for permanent installation.

C.2 Marking of temporary blinds Materials used shall be identifiable by marking.

For the purpose of identification and proper handling, temporary blinds shall be provided with a welded-on lifting lug which shall be marked with red paint and hard stamped with the nominal diameter (DN/NPS) and the maximum allowable test pressure.

C.3 Handling and assembly instructions Temporary blinds shall be mounted centred and as a minimum cover the entire flange sealing surface. The temporary blind shall not touch flange bolts after installation. Sealing surface of temporary blinds shall be flat, smooth and free of scale and/or other irregularities.

Unless otherwise instructed by purchaser in writing, temporary blinds shall be removed directly after pressure testing, after test systems were cleaned and dried.



Table C.1: Thickness of temporary blinds for flanges considering minimum yield strength of 235 MPa

DN NPS Maximum test pressure Pt [bar] 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185 190 195 200

15 0.5 1 1 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 5 5 20 0.75 1 2 2 2 2 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 25 1 1 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 7 7 7 7 40 1.5 2 2 3 3 3 4 4 4 4 5 5 5 5 5 6 6 6 6 6 6 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 8 9 9 9 9 50 2 2 3 3 4 4 4 5 5 5 5 6 6 6 6 6 7 7 7 7 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 10 10 10 10 10 10 65 2.5 2 3 4 4 5 5 6 6 6 6 7 7 7 8 8 8 8 9 9 9 9 10 10 10 10 10 11 11 11 11 11 11 11 11 12 12 12 12 13 13 80 3 3 3 4 5 5 6 6 7 7 7 8 8 8 9 9 9 10 10 10 10 11 11 11 11 11 11 12 12 12 13 13 13 13 13 14 14 14 14 14 14

100 4 3 4 5 6 6 7 7 8 8 9 9 10 10 10 11 11 11 12 12 12 13 13 13 13 13 14 14 14 14 15 15 15 15 16 16 16 17 17 17 17 150 6 4 6 7 8 9 10 10 11 11 12 12 13 14 14 15 15 16 16 17 17 17 18 18 18 19 19 20 20 20 21 21 21 21 22 22 23 23 23 24 24 200 8 5 7 8 10 11 12 13 14 14 15 16 17 18 18 19 19 20 21 21 21 22 23 23 23 24 24 25 26 26 26 27 27 27 27 28 28 29 30 30 30 250 10 6 9 10 12 13 15 16 17 18 19 19 20 21 22 23 23 24 25 26 26 27 27 28 29 29 30 30 31 31 32 32 33 33 34 34 35 35 36 36 37 300 12 7 10 12 14 16 17 18 20 21 22 23 24 25 26 27 28 28 29 30 31 32 32 33 34 34 35 36 36 37 38 38 39 39 40 41 41 42 42 43 43 350 14 8 12 14 16 18 20 21 23 24 24 27 28 29 30 31 32 33 34 35 36 37 38 38 39 40 41 42 42 43 44 44 45 46 47 47 48 49 49 50 50 400 16 9 13 16 18 20 22 24 26 27 29 30 31 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 49 50 51 52 53 53 54 55 56 56 57 450 18 11 15 18 21 23 25 27 29 31 32 34 35 37 38 39 41 42 43 44 45 47 48 49 50 51 52 53 54 55 56 56 57 58 59 60 61 62 62 63 64 500 20 12 16 20 23 25 28 30 32 34 36 37 39 41 42 44 45 46 48 49 50 51 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 600 24 14 19 23 27 30 33 35 38 40 42 44 46 48 50 52 53 55 56 58 60 61 62 64 65 66 68 69 70 72 73 74 75 76 77 79 80 81 82 83 84 700 28 16 22 27 31 34 37 40 43 46 48 51 53 55 57 59 61 63 64 66 68 70 71 73 74 76 77 79 80 82 83 84 86 87 88 90 91 92 93 95 96 750 30 16 23 28 32 36 40 43 46 48 51 53 56 58 60 62 64 66 68 70 72 74 75 77 79 80 82 83 85 86 88 89 91 92 94 95 96 98 99 100 101 800 32 18 25 30 35 39 43 46 49 52 55 57 60 62 65 67 69 71 73 75 77 79 81 83 85 86 88 90 91 93 95 96 98 99 101 102 104 105 106 108 109 900 36 20 28 34 39 44 48 51 55 58 61 64 67 70 73 75 78 80 82 85 87 89 91 93 95 97 99 101 102 104 106 108 110 111 113 115 116 118 119 121 122

1000 40 22 31 38 43 48 53 57 61 65 68 71 75 78 80 83 86 89 91 94 96 98 101 103 105 107 109 112 114 116 118 119 121 123 125 127 129 130 132 134 136 1100 44 24 34 41 47 53 58 62 67 71 75 78 82 85 88 91 94 97 100 103 105 108 110 113 115 118 120 122 124 127 129 131 133 135 137 139 141 143 145 147 149 1200 48 26 37 45 52 58 63 68 73 77 81 85 89 93 96 99 103 106 109 112 115 118 120 123 126 128 131 133 136 138 140 143 145 147 150 1300 52 28 40 48 56 62 68 74 79 84 88 92 96 100 104 108 111 115 118 121 124 127 130 133 136 139 142 144 147 150 1400 56 30 43 52 60 67 73 79 85 90 95 99 104 108 112 116 120 123 127 130 134 137 140 143 146 149 1500 60 32 46 56 64 72 79 85 91 96 101 106 111 116 120 124 128 132 136 140 143 147 150 1600 64 35 49 59 69 77 84 91 97 103 108 113 118 123 128 132 137 141 145 149 1800 72 39 55 67 77 86 94 102 109 115 122 128 133 139 144 149 2000 80 43 61 74 86 96 105 113 121 128 135 142 148