Industrial high-pressure pipelines carrying toxic, flammable, oxidising or high-temperature fluids demand the highest standards of fabrication, installation, inspection and testing. A single weld defect or improper support in a hydrogen, oxygen or ammonia pipeline can result in catastrophic fire, explosion or toxic release — with severe consequences for personnel, plant and the surrounding community.
We provide complete turnkey pipeline services — from isometric drawing interpretation and material procurement, through pipe spool fabrication in our IBR-certified workshop, to on-site erection, supports and hangers installation, insulation, hydraulic pressure testing, pneumatic leak testing, final documentation and handover. We handle pipelines from ½" NB to 24" NB, at design pressures from vacuum to 350 bar.
Our workforce includes ASME IX-qualified welders for GTAW (TIG), SMAW, FCAW and GMAW processes, with weld procedure qualification records (WPQRs) covering carbon steel, alloy steel, stainless steel (SS 304, 316, 321), duplex stainless steel, monel, inconel, hastelloy and titanium. All welders are regularly re-qualified and performance-tested.
We have successfully executed HP pipeline projects for power plants (steam, condensate, HP feed water lines), industrial gas distribution (N₂, H₂, O₂, Ar, CO₂), ammonia refrigeration systems, chemical process plants, oil & gas facilities, and research establishments — including ISRO, DRDO and BARC projects. All projects include complete documentation: material test certificates, weld map, radiography reports, hydrotest records and as-built drawings.
Our piping engineers interpret P&ID and isometric drawings, prepare material take-off (MTO) lists and procure pipes, fittings, flanges, gaskets and fasteners from CRISIL/BIS/ASTM-certified mills with material test certificates (MTCs). Positive Material Identification (PMI) testing using XRF analyser verifies alloy composition before fabrication for all stainless, alloy and non-ferrous materials.
Pipe spools are prefabricated in our IBR-certified workshop under controlled conditions using dedicated fit-up benches, mandrel pipe alignment clamps and preheat ovens. Joint identification, fit-up clearance (2–3mm root gap) and alignment (offset <1.6mm) are checked before welding. Tack welding and root pass are done by GTAW for critical HP and corrosive service lines. All weld joints are marked on the weld map for traceability to the welder and WPS.
Pipe spools are erected on-site using hydraulic pipe alignment clamps, precision chain hoists and pipe rollers. Pipe supports — springs, slide plates, rigid hangers, pipe shoes and anchor blocks — are installed per the stress analysis (CAESAR II) recommendations to control thermal expansion, vibration and dead weight without introducing unacceptable stress at nozzles and equipment connections. All field welds are done per qualified WPS with preheat verification.
All pressure-retaining welds in Class I piping (toxic, flammable, high-pressure service) are 100% radiographically tested (RT) per ASME B31.3. Class II piping (non-hazardous service) undergoes 10% random RT. Magnetic particle testing (MPT) or liquid penetrant testing (LPT) is performed on root passes for high-alloy materials. Hardness testing (BHN/HRC) is done post-PWHT. All NDE is performed by ASNT Level II certified technicians.
Completed pipeline sections undergo hydrostatic pressure testing at 1.5× design pressure (ASME B31.3) or 1.25× design pressure (ASME B31.1) using clean water (inhibited for carbon steel) with calibrated test gauges. Test pressure is held for a minimum of 30 minutes with no visible leaks, drops in pressure or distortion. Digital chart recorders document the pressure-time trace for inclusion in the test pack. Pneumatic testing with nitrogen at 1.1× design pressure is used where water is not permitted.
After hydrotest, pipelines are flushed with high-velocity water or nitrogen to remove mill scale, weld spatter, grit and moisture. Gas pipelines are purged with nitrogen to oxygen-free status (<1% O₂) before first gas introduction. All valves are functionally tested, gland packing adjusted, and actuators calibrated. Final leak test with sniffer or gas detector is performed at operating pressure. Full documentation package — weld records, NDE reports, test certificates — is handed over for statutory approvals.
| Pipe Size Range | ½" NB (DN 15) to 24" NB (DN 600) |
| Design Pressure | Vacuum to 350 bar |
| Design Codes | ASME B31.1 / B31.3 / B31.8 / IBR |
| Welding Processes | GTAW / SMAW / FCAW / GMAW / SAW |
| Welder Qualification | ASME Section IX (AWS D1.1 / IS 817) |
| Materials | CS / LTCS / SS 304 / 316 / Duplex / Alloy Steel / Inconel |
| NDE Methods | RT / UT / MPT / LPT / PMI / Hardness |
| Pressure Testing | Hydrotest 1.5× / Pneumatic 1.1× Design Pr. |
| Regulatory | PESO / IBR / Factory Act / PNGRB |
| Documentation | Weld Map / RT Reports / Test Records / As-Built |
Share your piping specifications, design code and timeline — we will provide a detailed method statement, schedule and competitive price within 5 working days.
