Vessel & Tank Inspection

Pressure test witnessing — independent hold-points.

Independent witnessing of hydrostatic and pneumatic pressure tests with hold-point sign-off for vessels, piping and equipment to ASME VIII, ASME B31.3 and API 510.

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Live GCS · Oman

Service overview

Independent assurance your equipment holds pressure.

A witnessed pressure test gives your client and AI confidence the equipment holds. GCS reviews the procedure, verifies gauge calibration, monitors pressurisation and hold, assesses any drop, and issues an independent witness certificate.

Scope of work

What we cover.

The complete range of activities included in this service line.

Procedure Review

Test pack, pressures and criteria checked

Calibration Check

Gauge and recorder calibration verified

Pressurisation Monitor

Controlled ramp and step-hold witnessed

Hold-Point Witness

Hold period and inspection at pressure

Leak / Drop Assessment

Pressure-drop and leak evaluation

Witness Certificate

Signed witness record and data sheet

Features & benefits

Why operators choose GCS.

Independent

Third-party reporting recognised by EPC and O&G majors in Oman.

Accredited

LEEA Full Member, ISO 17020 and ISO 17025 accredited delivery.

Fast mobilisation

Typically within 2 working days across Muscat, Sohar and Duqm.

Traceable records

Photographic reports and certificates issued within 5 working days.

Industry applications

Where this service is deployed.

Pressure Test Witnessing supports asset integrity and statutory compliance across Oman’s heavy industry.

Oil & GasPetrochemicalRefiningPower GenerationWater & DesalinationFertiliserEPC ContractorsStorage Terminals

Standards & compliance

Frameworks we work to.

Every report references the applicable code so your QA, client and insurer can audit decisions back to source.

ASME VIIIASME B31.3API 510PEDASME PCC-2

Service process

How the job runs.

A repeatable, auditable sequence from enquiry to certificate.

Stage 01

Procedure review

Test procedure, calibration certificates and acceptance criteria agreed before start.

Stage 02

Set-up & isolation

Rig, gauges and safety isolations verified; exclusion zone established.

Stage 03

Test execution

Controlled pressurisation or loading to the specified value with hold period.

Stage 04

Witness & record

Readings logged at each hold point; pass/fail assessed against criteria.

Stage 05

Certify

Witness certificate and data record issued within 5 working days.

Equipment & technology

Tools of the trade.

Calibrated, traceable instruments operated by qualified technicians — every tool carries a current calibration certificate.

Hydraulic test pumpsCalibrated load cellsDigital pressure loggersProof-load test bedsMaster shackles & linksDead-weight testers

Frequently asked

Questions our clients ask most often.

Why use an independent pressure-test witness?+

An independent witness verifies the test was performed to the approved procedure with calibrated instruments, and provides a defensible record for your client, Authorised Inspector and insurer — removing any conflict of interest.

Do you witness both hydrostatic and pneumatic tests?+

Yes. We witness hydrostatic (water) and pneumatic (air/nitrogen) tests. Pneumatic tests carry higher stored-energy risk, so we pay particular attention to exclusion zones, step-holds and safety procedures.

What certification do you issue?+

A formal report with photographs, defect lists and recommendations, plus a Certificate of Conformity citing the specific clause references. Hard-copy and electronic certificates are available, and records are retained for audit.

How quickly can GCS mobilise pressure test witnessing in Oman?+

For routine work in Muscat, Sohar or Duqm, mobilisation is typically within 2 working days. Emergency and post-incident jobs can be mobilised same-day, with reports issued within 5 working days.

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