Frequently asked questions

Start from the service condition, not the catalogue. The medium rules out body and trim materials first. Pressure and temperature fix the minimum pressure class from the ASME B16.34 rating table. Function then narrows the type: isolation, throttling, check or protection. Send all four values and the reply is a selection, not a list. Confirm against the current edition.

See also → Valve selection by service condition · Valve selection by standard

A pressure class (150, 300, 600 and upward) is a rating family from ASME B16.34. Allowable working pressure falls as temperature rises, by material group. A WOG figure (water, oil, gas) is a single cold working pressure, with no temperature curve behind it. They are not interchangeable: a WOG valve needs the manufacturer's own derating above ambient.

See also → ASME B16.34 pressure and temperature ratings · Valve selection by standard

Seawater is a pitting problem. Gulf seawater is high in chloride at high ambient temperature. Standard 316 stainless sits below the pitting-resistance threshold most specifications demand. Super-duplex, nickel-aluminium bronze or lined bodies are the candidates, and ASTM G48 separates them. The designations a super duplex valve material order must carry are set out separately. Chilled water is the opposite: the risk is the seat, not the body. Specify a soft seat holding bubble-tight shut-off.

See also → Valve selection by standard · Valve selection by standard

A pressure-independent control valve combines the control valve and the differential-pressure regulator in one body. The terminal's flow stays at the design value as network pressure moves. A static balancing valve is set once at commissioning and drifts thereafter. On variable-flow district-cooling terminals, the PICV is usually the better fit. Static balancing still earns its place on constant-flow circuits and as a measurement point.

See also → PICV vs balancing valve for chilled water · District cooling & HVAC guide

An energy-transfer station is a short run of pipe with a long valve list: isolation either side of the heat exchanger and the strainer, the strainer itself, a differential-pressure control valve or PICV on the primary, a two-port control valve on the secondary, check valves on the pump discharge, and test, drain and vent points. Each sits at a different pressure class, and each has its own failure mode.

See also → District-cooling valve selection in the Gulf · District cooling & HVAC guide

Size it on flow, not on pipe diameter. A pressure-reducing valve is selected from the flow rate, the inlet pressure range and the set outlet pressure. The maker's capacity table converts those into a valve size, often smaller than the line. Oversizing is the common error: the valve hunts and wears its seat. On steam, check whether two stages are needed.

See also → How to size a pressure-reducing valve · Steam, pressure & protection guide

Both open automatically to protect equipment from overpressure. A safety valve pops fully open at its set pressure and is used on compressible fluids: steam, air and gas. A relief valve opens progressively with the overpressure and is used on liquids. Safety-relief valves cover both. State the set pressure, the capacity, the medium and the back pressure on the enquiry.

See also → Pressure, safety & steam valves · Steam, pressure & protection guide

Match the trap to the application before the size. Thermodynamic traps suit steam mains and tracing. Mechanical float traps suit process equipment with varying load. Thermostatic traps suit tracing and low-load lines. Each is sized on condensate load and differential pressure. Too fine a strainer mesh becomes the blockage.

See also → Steam trap selection guide · Steam, pressure & protection guide

EN 10204 defines the inspection documents that accompany metallic products. A type 3.1 certificate states that the material complies with the order, with test results from the maker's own inspection department. Type 2.2 states compliance with non-specific results; type 3.2 adds a third-party witness. Ask for 3.1 where the body's material grade is part of the design case. Availability is confirmed per order.

See also → Valve documentation: MTCs and test certificates · Sourcing & documentation guide

Both describe pressure testing of finished valves: a shell test above the rating and a seat test at or near it. API 598 is written for the petroleum industry and is what most steel-valve specifications call for. ISO 5208 defines leakage as classes, from rate A (no visible leakage) downward. State which document and which class your specification names.

See also → Valve documentation: MTCs and test certificates · Sourcing & documentation guide

Two separate qualifications. Fire-safe (API 607 for quarter-turn soft-seated valves, API 6FA for the API 6D family) means a valve of that design was burned under test and still limited leakage. Fugitive emission (ISO 15848-1) classifies how little the stem seal leaks over a set number of cycles. A fire-safe valve is not automatically low-emission, nor the reverse.

See also → Fire-safe valves: API 607 vs API 6FA · Sourcing & documentation guide

All three are confirmed per enquiry against the service condition. A valve is priced once its class, material, size, end connection and documentation are fixed. Lead time depends on whether that specification is available or made to order. We do not publish stock levels or promise delivery dates on this site. Send the condition and the quantity.

See also → Choosing a valve supplier in Dubai · Sourcing & documentation guide

Yes. Valve testing, maintenance and repair are one of the three services, alongside selection and supply. Scope is agreed per enquiry: pressure and seat testing to the referenced standard, planned maintenance, and repair where it is economic against replacement. Location and turnaround are stated on the quotation, not promised here.

See also → Technical support & testing · Sourcing & documentation guide

Use the enquiry form and state the service condition first: medium, operating and design pressure and temperature, size, end connection and quantity. Add the governing specification and any certificate requirement, such as a 3.1 material certificate. The more the enquiry carries, the more the reply can be a selection.

See also → Send an enquiry · Sourcing & documentation guide