ls 133-01 (en)

Pressure test of pressure vessels and piping at suppliers

LINDE STANDARD

LS 133-01

of 4

Remarks on the current issue:

Revision: Clauses 5, 6 and 7 changed, editorially revised. Previous issues: 10.94, 03.2002, 06.2007 Responsible department(s) for the technical content: TAW Confidentiality class 1 in accordance with LS 104-03: Unrestricted publication

X 04 10.2008 TAW/Körner TAW/Kittel TAW-N/Thomas Status Issue Date Prepared Checked Approved

© Linde AG LS 133-01(EN)

Contents

1 Scope and purpose ...........................................2 2 Normative references........................................2 3 Scheduling of the pressure test.........................2 4 Test method ......................................................2 5 Preparation........................................................2 6 Hydrostatic tests................................................3 7 Pneumatic tests.................................................3 8 Test results and report ......................................3

Linde Engineering Division Issue 04/10.2008 LS 133-01 of 4


1 Scope and purpose This standard shall apply for pressure testing of pressure vessels and piping with water or gases at suppliers in addition to the applicable codes and standards. During the pressure test it shall be confirmed that the pressure-retaining shell is properly designed and manufactured to resist to the test pressure and that no safety-critical deformations occur. Job-specific or component-specific regulations/specifications and regulations of local authorities shall govern.

2 Normative references This standard contains provisions which, through undated references in this text, constitute provisions of other publications. The normative references are cited at the respective part in the text and the publications are listed below. Issues valid at the time of placement of order shall govern.

ASME VIII Div. 1 Rules for Construction of pressure vessels LS 105-01 Part 1 Girth and manhole flange connections – Assembly instruction

3 Scheduling of the pressure test Pressure testing shall be performed after completion of all manufacturing processes and examinations on the pressure-retaining shell, but prior to applying painting, insulation, rubber coating, brick-lining, metallic liners and similar coating to the inside and outside shell. For pre-fabricated piping Linde accepts a single-layer outside primer. The cover plates of "plates and frame heat exchangers" (bolted), may be completely painted before pressure test.

4 Test method The standard test method is the pressure test, using water as test fluid. If in exceptional cases, e. g. due to process reasons, the hydrostatic test is not suitable or only possible with extreme high effort, a pneumatic pressure test might be requested; if the applicable code allows it and upon prior acceptance by Linde. For pressure vessels with different chambers, each pressure chamber shall be tested.

5 Preparation In advance performed tests and inspections shall be finalised with a satisfactory result. The test pressures and the requirements for the performance shall be in compliance with the specified code and shall be taken from the approved documents of the manufacturer. If pressure testing is performed in the presence of Linde personnel, a safety concept for the personal protection shall be presented. Prior to the pressure test covered welds (e. g. under reinforcing pads or saddle plates) shall be subject to a gas leak test (min. 0,5 bar overpressure with a halide-free, foam-frothing agent). Vent holes (e. g. in reinforcement pads or saddle plates) shall be open during pressure test. Calibrated measuring instruments (pressure gauge, pressure transmitter) with a measuring range ≤ 1,5 x test pressure shall be used, if not required differently by the applicable code (e. g. ASME VIII, Div. 1, UG-102; 1,5 - 4 x test pressure). For pneumatic tests 2 measuring instruments working independently from each other shall be used. For the assembly of the pressure vessel flange connections the specified original gaskets shall be used. This requirement is valid for all flanged connections as i. e. manholes, drains and vents, if the manufacturer also delivers the blind flange and the gasket. The flanged connections shall be assembled acc. to LS 105-01 Part 1.



6 Hydrostatic tests The test fluid shall be clean water of potable water quality - permissible chloride content (including bromides, iodides) according to table 1 - other water qualities upon approval by Linde. The material data given in table 1 shall apply to all surfaces being in contact with water, i. e. also to gaskets, internals and claddings. For constructions involving material combinations, the more stringent requirement shall apply. Vent holes (e.g. in reinforcement pads or saddle plates) shall be open during pressure test. The holding time is at least 30 min. After pressure testing water shall immediately be drained. Vents shall be opened to avoid the built-up of vacuum. Deposits like rust and sludge shall be removed immediately by flushing with clean water. All surfaces shall be vented until drying is complete.

7 Pneumatic tests • Safety precautions shall be verified / confirmed prior to the pressure test. • The test medium shall be an inert, oil-free and dry gas, normally air or nitrogen. • Pressurization and pressure measurement shall be ob observed from a safe distance. • First a leak test at 0,5 to 1 bar overpressure by visual examination of the welds and detachable

connections after wetting with foam-frothing agent shall be carried out. • At test pressure the holding time shall be at least 30 min (no access is permitted during holding time

above max. allowable working pressure). • Access to the safety area is permitted only after decrease of the test pressure to the maximum

allowable working pressure. • The residues of the foam-frothing agent shall be washed off immediately after the pressure test,

otherwise the danger of corrosion is existing.

8 Test results and report The requirements are fulfilled, if - no inadmissible deformations are found and - no liquid is leaking during the hydrostatic test or - no formation of foam is detected during the leak test or - no leakages during the pneumatic test; for non-metallic gaskets on pipe flanges uniformly occurring fine-pored foam (without local formation of bubbles) is, however, admissible.

The pressure test shall be documented in a test report by the manufacturer or the inspection agency indicating the applicable regulation and code, the equipment tested, test pressure, test fluid, test results and date and, if necessary, test temperature, pressure gauge No., reference to calibration certificate, pressure record. In case of a not accepted pressure test, Linde shall be informed immediately. The further proceeding shall then be agreed upon with the Linde and the inspection agency.



Table 1: Admissible chloride content of the water for hydrostatic tests

Ser. Material group Material examples Chloride content No. EN (DIN) ASTM ppm = mg/l 1 Ferritic steels,

unalloyed/low-alloy, welded with ferritic filler metals

1.0305 1.0425 1.5415 1.7335 1.7380 1.5637

A 53, A 106 A 335 P1, P11, P12 A 333 Gr. 1, 3, 6

< 250

2 Ferritic-austenitic steels, Mo-alloyed (duplex steels)

1.4462 1.4410

3 Stainless 18/9- CrNi-steels, Mo-alloyed

1.4571 1.4404 1.4429 1.4449

Type 316 316L 317

< 150

4 Stainless 18/9- CrNi-steels without Mo

1.4301 1.4306 1.4541 1.4550

Type 304 304L 321

5 Stainless, ferritic Cr-steels 1.4006 1.4016 1.4922

Type 410, 430

6 Ferritic steels, welded with austenitic filler metals

1.5662 A 353 A 553

< 50

7 Heat-resistant, austenitic steels (CrNi, NiCr) and Ni-base alloys

1.4841 1.4876 1.4959

Type 310 Alloy 800

8 Aluminium materials AlMn AlMg4,5Mn

Alloy 3003 5083

9 Copper materials Copper Brass

Copper Brass

no

10 Plastic materials GRP, PE, PP limitation

ls 133-01 (en)

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