| Quality Standards | Pressure-vessel design basis | Confirm the design pressure, operating pressure, design temperature, hydrostatic test pressure, and allowable material stress for every housing model. | Request signed design calculations, pressure-test procedures, drawings, and material certificates. The applicable design code should be stated clearly. | Mandatory |
| Applicable pressure regulations | For regulated markets, the housing may require compliance with a recognized pressure-equipment framework, depending on volume, pressure, fluid group, and local legislation. | Examples include ASME Boiler and Pressure Vessel Code Section VIII, the EU Pressure Equipment Directive 2014/68/EU, or an equivalent national code. | Market-specific |
| Material traceability | Common wetted materials include stainless steel 304/304L and 316/316L. Material selection should match chloride level, pH, temperature, and process chemistry. | Check heat numbers, mill test certificates, chemical composition, mechanical properties, and traceability from raw material to finished housing. | Mandatory |
| Welding quality | Welded stainless-steel housings should have controlled welding procedures, qualified operators, suitable shielding gas, and documented weld inspection. | Review WPS/PQR documentation, welder qualifications, visual inspection records, dye-penetrant testing where specified, and weld-repair procedures. ISO 3834 may be used as a quality framework. | Recommended |
| Factory quality management | A documented quality system should control incoming materials, in-process inspection, final testing, nonconforming products, and corrective actions. | Verify a current ISO 9001 certificate issued for the actual manufacturing site, together with internal inspection records and calibration certificates. | Recommended |
| Performance Data | Housing pressure rating | Common industrial configurations are designed around nominal pressure classes such as 6 bar, 10 bar, or 16 bar, but the actual rating depends on design, size, temperature, and code. | Do not rely only on a catalog value. Check the nameplate, design drawing, temperature derating, pressure-test report, and applicable code calculation. | Verify by model |
| Cartridge length compatibility | Frequently used cartridge lengths include approximately 10, 20, 30, and 40 inches. DOE and 222/226/S codes require matching end connections. | Confirm cartridge dimensions, sealing method, end-cap configuration, available adapters, and dimensional tolerances before purchase. | Typical range |
| Number of cartridges | Single-round housings are used for low flow rates, while multi-round housings may contain several cartridges to increase flow capacity and reduce changeout frequency. | Request the recommended flow range based on the actual cartridge type, viscosity, contaminant loading, allowable pressure drop, and replacement interval. | Application-dependent |
| Connection options | Typical process connections include threaded, sanitary clamp, flanged, and welded connections. Common nominal sizes range from approximately 1/2 inch to 4 inches for many industrial applications. | Check connection standard, nominal size, face-to-face dimensions, port orientation, gasket material, and compatibility with existing piping. | Confirm before order |
| Pressure-drop measurement | A differential-pressure gauge, transmitter, or gauge port helps determine cartridge loading and the correct replacement point. | Check gauge range, accuracy, wetted materials, connection size, isolation valve, and whether the supplier provides a clean-filter pressure-drop baseline. | Strongly recommended |
| Drain and vent arrangement | Drain ports and vent ports should allow safe depressurization, complete draining, and reduced air entrapment during startup. | Verify drain and vent size, location, valve type, dead-leg risk, and whether the arrangement suits the process fluid and cleaning method. | Application-dependent |
| Customization | Material customization | Options may include 304/304L, 316/316L, carbon steel with protective coating, or special alloys for more aggressive fluids. | Require a written material specification, corrosion-compatibility review, surface-finish requirement, and confirmation of all wetted and non-wetted materials. | Document in quotation |
| Surface finish | Industrial housings may use a standard pickled/passivated or polished finish. Hygienic applications commonly specify a smoother internal finish, often around Ra ≤ 0.8 µm where required. | Request the specified Ra value, measurement method, polishing direction, passivation method, and surface-finish inspection report. | Specify numerically |
| Sealing materials | Common gasket and O-ring materials include EPDM, NBR, FKM, PTFE, and silicone. Selection depends on temperature, chemicals, and regulatory requirements. | Check compound grade, temperature range, chemical compatibility, extractables requirements where relevant, and spare-seal availability. | Fluid-specific |
| Special process connections | Custom port orientation, sanitary clamps, tri-clamp fittings, flanges, threaded ports, sampling ports, and instrument connections can be incorporated into the design. | Approve a dimensioned drawing showing all port sizes, centerlines, orientations, tolerances, and connection standards before production. | Drawing approval required |
| Automation and monitoring | Optional features may include differential-pressure transmitters, automatic drain valves, vent valves, level switches, and PLC-compatible instruments. | Check instrument range, electrical classification, output signal, enclosure rating, calibration certificate, and control-system interface. | Optional |
| Documentation package | A project-specific document package may include approved drawings, inspection plans, material certificates, pressure-test reports, certificates of conformity, and operating instructions. | Define the document list, language, format, approval stages, and submission schedule in the purchase specification. | Recommended |
| Production Capabilities | Manufacturing process | A capable production line should cover cutting, forming or machining, fit-up, welding, surface treatment, assembly, pressure testing, inspection, and final packing. | Review the process flow, equipment list, inspection points, production records, and whether critical operations are performed in-house or subcontracted. | Audit preferred |
| Fabrication range | Confirm the smallest and largest housing diameter, overall length, cartridge count, wall thickness, connection size, and maximum finished weight that the facility can produce. | Request representative drawings, production photographs, dimensional inspection records, and a list of standard and non-standard configurations. | Capacity check |
| Welding and inspection equipment | Typical equipment may include TIG welding systems, orbital welding equipment for sanitary work, welding-positioning tools, surface-treatment facilities, and calibrated inspection instruments. | Verify equipment maintenance, operator qualifications, weld inspection capability, and calibration status of pressure gauges and measuring tools. | Recommended |
| Pressure testing capability | Each completed pressure housing should undergo a documented pressure or leak test appropriate to its design code and service conditions. | Check test medium, test pressure, holding time, acceptance criteria, calibrated gauge identification, test date, and inspector signature. | Mandatory |
| Production capacity and lead time | Lead time varies with material availability, cartridge count, customization, regulatory documentation, and order quantity. It should be stated as a confirmed production schedule rather than a general promise. | Request monthly capacity, current order loading, standard lead time, engineering review time, inspection time, and contingency arrangements for delays. | Confirm in writing |
| Packaging and export readiness | Housings should be protected against impact, moisture, contamination, flange damage, and movement during inland and international transport. | Check protective caps, internal packaging, wooden-case treatment where required, packing list, product identification, and export documentation. | Required for export |
| Supplier Verification | Technical quotation quality | A complete quotation should identify model configuration, design pressure, material, cartridge size, connection standard, gasket material, surface finish, accessories, and exclusions. | Reject quotations that provide only a unit price without a datasheet, drawing, technical deviations, and clearly defined delivery scope. | Mandatory |
| Sample and first-article inspection | For customized housings, a first article or sample inspection can verify dimensions, connection alignment, cartridge fit, weld quality, finish, and pressure-test performance. | Use an approved inspection checklist with measurable acceptance criteria before mass production. | Recommended |
| Traceability and identification | Each housing should have durable identification showing at least model or serial number, material, design pressure, test pressure where applicable, and manufacturing date. | Confirm that the nameplate information matches the approved drawing, material certificates, pressure-test report, and shipping documents. | Mandatory |
| After-sales support | Important support items include replacement seals, cartridge compatibility guidance, operating instructions, troubleshooting, warranty terms, and response time for technical claims. | Check spare-parts availability, warranty coverage, technical contact process, and procedures for nonconforming products. | Evaluate before purchase |
| Total cost of ownership | Evaluate housing price together with cartridges, seals, pressure instruments, spare parts, freight, import costs, maintenance time, and expected replacement frequency. | Compare suppliers using the same technical specification and calculate cost per operating cycle rather than comparing purchase price alone. | Use for final selection |
