Pressure Vessels

What is a pressure vessel?

A pressure vessel is a specially engineered container designed to hold gases or liquids at pressures substantially different from atmospheric pressure. Pressure vessels are critical components across industries—from compressed air receivers and chemical reactors to heat exchanger shells, storage tanks, and composite overwrapped pressure vessels (COPVs). Safety, material selection, code compliance, and precision fabrication are essential to reliable pressure vessel performance.

At United Heat Exchangers, we design and manufacture high-performance, ASME-certified pressure vessels tailored to demanding industrial environments. Our solutions combine code-compliant engineering, robust materials, and stringent quality control to deliver long service life, safety, and operational efficiency.

Why Choose Our Pressure Vessels?

• ASME & International Code Compliance: Designs follow ASME Section VIII (Div. 1 & 2) and other applicable international standards to meet statutory and industry requirements.
• Custom Engineering: Bespoke vessels adapted to process needs, pressure/temperature profiles, cyclic duty, and footprint constraints.
• High-Quality Materials: Carbon steel, stainless steels (304/316/316L), duplex/super duplex alloys, nickel alloys, and specialty linings for corrosion resistance.
• Advanced Fabrication: CNC profiling, precision welding (SMAW, GTAW, SAW), full radiography, and non-destructive testing (NDT).
• Comprehensive QA/QC: Hydrostatic testing, PMI, hardness checks, and dimensional inspections with complete documentation.
• Turnkey Support: Design, fabrication, inspection, lifting & installation guidance, spares, and lifecycle maintenance programs.

Typical Applications

Pressure vessels from United Heat Exchangers serve multiple industries:

• Oil & Gas: separators, scrubbers, slug catchers, storage spheres.
• Petrochemical & Chemical: reactors, autoclaves, surge drums, solvent storage.
• Power Generation: feedwater heaters, steam drums, condensate receivers.
• HVAC & Refrigeration: refrigerant receivers, pressure receivers.
Pharmaceuticals & Food Processing: pressure reactors, sterilization vessels (ASME and hygienic finishes available).
• Aerospace & Defense: composite overwrapped pressure vessels (COPVs) and test vessels.

Types of Pressure Vessels We Offer

• Horizontal and Vertical Cylindrical Vessels—standard industrial vessels for storage, separation, and heat transfer.
• Spherical Vessels—ideal where uniform stress distribution is required for high pressures.
• Atmospheric Storage Tanks—low-pressure bulk storage with robust seals and coatings.
• Composite Overwrapped Pressure Vessels (COPVs)—lightweight, high-strength solutions for specialized applications.
• Heat-Exchanger Shells & Jacketed Vessels—combined pressure containment and heat transfer capability.
• Pressure Vessels with Internals—baffles, demisters, trays, packings, and support structures integrated per process needs.

Materials & Corrosion Resistance

Selecting the right material is central to pressure vessel longevity and safety:

• Carbon Steel (SA516 Gr.70 / ASTM A36): Cost-effective for non-corrosive fluids and moderate temperatures.
• Stainless Steel (304, 316, 316L): Excellent corrosion resistance for wet and corrosive environments; suitable for food and pharma.
• Duplex & Super Duplex: Higher strength and corrosion resistance for chloride-rich or offshore environments.
• Nickel Alloys (Inconel, Hastelloy): For extremely corrosive or high-temperature services.
• Clad & Lined Vessels: Carbon steel base with corrosion-resistant cladding or internal lining (rubber, PTFE, epoxy) where cost and corrosion resistance must be balanced.

Design Standards & Safety

Design and fabrication follow internationally recognized codes and best practices:

• ASME Section VIII (Div. 1 & 2):—primary code for welded pressure vessels.
• PED (Pressure Equipment Directive): for EU projects.
• EN, API, IS (Indian Standards): and client-specific specifications.
• Finite Element Analysis (FEA): used for complex nozzles, saddles, and nozzle-to-shell transitions where stress concentration is critical.
• Seismic & Wind Loading Considerations: Structural design adapted to site requirements.
• Design for Fatigue & Cyclic Duty: Required when pressure or thermal cycling is frequent.

How Our Pressure Vessels Are Manufactured

1. Engineering & CAD Modeling: 3D models, BOM, nozzle layout, and stress calculations.
2. Material Procurement & Traceability: Mill test certificates (MTCs) and full material traceability.
3. Plate Cutting & Rolling: CNC cutting, plate rolling for shell formation.
4. Welding & Assembly: Skilled welding procedures (WPS/PQR), tack-up, and full penetration welds.
5. Non-Destructive Testing (NDT): Radiography (RT), ultrasonic testing (UT), magnetic particle (MPI), and dye penetrant (DPI) as required.
6. Surface Treatment & Coating: Blasting, primer, epoxy or polyurethane coatings; internal linings where required.
7. Testing: Hydrostatic testing, pneumatic testing (where permitted), and leak testing.
8. Final Inspection & Documentation: Dimensional check, painting, fitment of accessories, test certificates, and QA pack.

Standard Features & Typical Accessories

• Manways and access covers
• Nozzles (flanged, welded, threaded) sized per process needs
• Lifting lugs, saddles, and support structures
• Pressure relief valves, rupture discs, and safety devices
• Instrumentation ports and sight glasses
• Drain and vent connections
• Insulation jackets and heat tracing provisions (if required)
• External supports, platforms, ladders, and walkways (for larger vessels)

Technical Specifications — Product Matrix

Note: The table below is an illustrative example. Final specifications are customized per project.

Parameter	Typical Options
Design Codes	ASME Section VIII Div 1 / Div 2, PED, API
Orientation	Horizontal / Vertical / Spherical
Capacity	50 L — 500,000 L (custom)
Design Pressure	Vacuum to 1000 bar (application dependent)
Design Temperature	-196°C to 600°C+ (material dependent)
Materials	Carbon Steel, SS304/316/316L, Duplex, Nickel Alloys
Joints	Fully welded (SMAW/GTAW/SAW)
Testing	Hydrotest, RT/UT, PMI, Hardness, MPI/DPI
Coating	Epoxy, Polyurethane, Cladding, Lining

How to Choose the Right Pressure Vessel

When selecting a pressure vessel, consider:

• Process Fluid Properties: Corrosivity, toxicity, viscosity, solids content.
• Operating Pressure & Temperature: Dictates material selection and code.
• Service Cycle: Static storage vs. frequent cycling affects fatigue life.
• Capacity & Footprint Constraints: Volume, height, and plant layout.
• Regulatory & Safety Requirements: Local statutory requirements, safety margins.
• Inspection & Maintenance Accessibility: Manways, skids, and support design.
• End-of-Life & Replacement Considerations: Removable internals, corrosion allowance.

We provide a free initial process review and proposal to match the optimal vessel type and design to your application.

Installation & Commissioning

Our scope can include:

• On-site supervision of lifting and positioning.
• Alignment and piping tie-ins per client isometrics.
• Installation of safety devices, vents, and instrumentation.
• Hydrostatic and leak testing at the site (as allowed).
• Commissioning assistance, including first-run operational support and pre-start safety checks.

Installation guidance includes detailed lifting plans, anchor bolt layouts, and scaffold/access recommendations to ensure safe, code-compliant commissioning.

Maintenance, Inspection & Lifecycle Support

Proper maintenance ensures safety and extends service life:

• Routine Visual Inspections: External corrosion, leakage, and weld cracks.
• NDT Inspections: Periodic RT/UT to monitor wall thickness and weld integrity.
• Corrosion Monitoring: Ultrasonic thickness surveys and corrosion coupons.
• Pressure Relief Device Testing: Regular testing and replacement cycles.
• Surface Re-coating & Lining Repair: Scheduled based on service conditions.
• Spare Parts & Consumables: Nozzles, gaskets, fasteners, and relief devices on supply.
• Refurbishment & Re-rating Services: For life extension or repurposing.

United Heat Exchangers provides tailored maintenance contracts and on-site services to minimize downtime.

Quality Assurance & Documentation

Each vessel is delivered with a comprehensive documentation pack:

• Material Test Certificates (MTCs) for all primary materials.
• Welding Procedure Specifications (WPS), Procedure Qualification Records (PQR).
• Inspection and Test Plans (ITP) and NDT reports.
• Hydrostatic test certificates and dimensional drawings.
• As-built drawings and operation & maintenance manuals.
• Certification as per ASME, PED, or client-specified standards.

We maintain strict traceability and calibration controls to support statutory inspections and audits.

Safety Considerations

Safety is non-negotiable for pressure vessels. Key measures include

• Correct relief device sizing and redundancy.
• Adequate corrosion allowance and protective liners.
• Proper welding controls and qualified welders.
• Regular competence-based inspection schedules.
• Clear labeling of pressure ratings and operating limits.
• Emergency procedures and safe isolation points.

We also recommend independent third-party inspection for critical high-pressure or hazardous services.

Environmental & Sustainability Considerations

• Material Efficiency: Optimized wall thickness and design margins reduce material usage without compromising safety.
• Corrosion-Resistant Options: Longer life reduces environmental impact from replacements.
• Leak Prevention: Robust sealing and testing protocols prevent fugitive emissions.
• Energy Savings: Jacketed or insulated vessels minimize process energy losses where applicable.
• End-of-Life Recycling: Metal components are fully recyclable; we provide guidance for responsible disposal.

Typical Lead Times & Delivery

Lead times depend on vessel size, material, complexity, and approvals. Standard small to medium vessels are typically delivered within weeks, while large fabricated vessels may require months. We provide a transparent project schedule at the RFQ stage and can often fast-track critical deliveries.

Case Studies (Short Summaries)

• Oil & Gas Separator: Custom vertical separator with duplex internals for offshore platform; delivered with full NDT and site commissioning.
• Chemical Reactor: Jacketed stainless steel reactor with sanitary finishes and CIP access for specialty chemicals.
• High-Pressure Storage Sphere: ASME-certified spherical vessel for compressed gas storage with seismic supports and automatic safety systems.

(Full project details available on request—NDA protected where required.)

Pricing & Quotation Process

To provide an accurate quotation, we require:

• Process data sheet (fluid, flow, pressure, temperature)
• Required codes and certifications (ASME, PED, API, etc.)
• Preferred materials and any special coatings or internals
• Site limitations (transport, lifting, access)
• Delivery schedule and inspection requirements

Submit your RFQ and drawings to our engineering team for a detailed cost estimate and technical proposal.

Our Commitment

United Heat Exchangers is committed to delivering pressure vessels that meet your process needs and regulatory demands. Our engineering expertise, quality systems, and industry experience ensure dependable pressure containment solutions that maximize uptime and minimize lifecycle cost. Partner with us for engineered pressure vessels you can trust.

Ready to specify a pressure vessel that’s safe, efficient, and built to last? Contact United Heat Exchangers today for a free technical consultation and fast, competitive quote.

Contact Us

Frequently Asked Questions (FAQ)

1. Are your pressure vessels ASME certified?

Ans: Yes—we design and manufacture ASME-certified vessels and can provide ASME U-stamps and associated documentation as required.


2. What inspections are performed before delivery?

Ans: We perform dimensional checks, hydrostatic testing, radiography/ultrasonic testing, PMI, visual and dimensional inspections, and supply a complete test report pack.


3. Can you supply vessels with special linings?

Ans: Yes. We supply rubber linings, PTFE linings, epoxy coatings, and stainless cladding depending on corrosion needs.


4. Do you offer turnkey installation?

Ans: Yes—we offer on-site installation supervision, piping tie-in assistance, and commissioning support.


5. How do you handle lifting and transport?

Ans: Every vessel is supplied with a lifting plan, identified lifting lugs, and transport supports. For oversized cargo, we assist with routing and logistics planning.


6. What is the maximum pressure you can design for?

Ans: We design vessels across a broad pressure range—from vacuum up to extremely high pressures—subject to materials and code limits. Provide process details for a precise answer.