| 1 |
Trunnion-Mounted Ball Valve |
Pipeline isolation, wellhead flowlines, gathering systems and high-pressure block-and-bleed service; commonly specified in ASME Class 600–2500. |
Carbon or low-alloy steel pressure boundary with sour-service qualification; 316L, 22Cr duplex or nickel-alloy wetted components where corrosion resistance requires it. |
Carbon and low-alloy steel components require hardness control, suitable heat treatment and resistance to sulfide stress cracking. Stainless and nickel alloys must be selected within the applicable environmental limits of MR0175/ISO 15156. |
Body: commonly screened around 0 to +60°C for carbon/low-alloy sour-service applications. Lower temperatures require impact-toughness qualification. Alloy limits are grade- and environment-specific. |
Use metal or polymer seats selected for pressure, temperature and H₂S compatibility. PTFE and PEEK temperature ratings are grade-dependent; elastomer limits must be checked against rapid gas decompression. |
Confirm cavity relief, double block and bleed, fire-safe design, fugitive-emission requirements and full material traceability. |
| 2 |
Slab or Expanding Gate Valve |
Pipeline isolation, wellhead and Christmas-tree systems, refinery feed isolation and high-pressure transmission lines; commonly used in Class 600–2500. |
Sour-service carbon or low-alloy steel body; corrosion-resistant alloy trim, stem and overlay options selected according to the fluid chemistry. |
Body, bonnet, stem, gate and pressure-retaining fasteners need separate material and hardness review. Weld overlays and heat-affected zones require qualification for sour service. |
Body: often screened around 0 to +60°C for carbon/low-alloy sour applications. Minimum temperature depends on impact testing and applicable pressure design code. |
Metal seats are preferred for abrasive or high-pressure service. Soft-seat materials require compatibility review for H₂S, hydrocarbons, temperature cycling and decompression. |
Check full-bore requirements, piggability, seat leakage class, stem sealing, drain/vent arrangements and actuator torque at the lowest temperature. |
| 3 |
Globe Valve |
High-pressure throttling, pressure control, bypass systems, steam or hydrocarbon regulation and severe-service control applications; commonly specified in Class 600–1500. |
Carbon or low-alloy steel body for qualified sour service; 316L, duplex or nickel-alloy trim for corrosion, erosion or high-velocity service. |
Trim hardness, galling resistance, weld repair procedures and compatibility with the actual H₂S partial pressure, chloride content, pH and temperature must be verified. |
Body: commonly screened around 0 to +60°C for carbon/low-alloy sour applications; cryogenic or elevated-temperature service requires a separate material qualification. |
Use hardened trim only when the hardness and material combination remains acceptable for sour service. Graphite packing is often used at elevated temperature, subject to emission and chemical compatibility requirements. |
Specify the required flow characteristic, cavitation resistance, noise limit, allowable pressure drop and actuator fail position. |
| 4 |
Pressure-Seal Check Valve |
Compressor discharge, pump discharge, injection systems and high-pressure process lines; commonly used in Class 600–2500. |
Carbon or low-alloy steel body with sour-service qualification; stainless or nickel-alloy hinge, disc, seat and trim components where required. |
All pressure-retaining and wetted parts must be reviewed, including hinge pins, springs, bolting and hard-facing materials. Avoid unqualified high-hardness components in wet H₂S exposure. |
Body: often screened around 0 to +60°C for carbon/low-alloy sour service; minimum design temperature requires impact-test confirmation. |
Disc-to-seat materials should be selected for reverse-flow prevention, erosion and tight shutoff. Spring materials require particular attention to sulfide stress cracking and corrosion fatigue. |
Verify cracking pressure, installation orientation, dynamic stability, slam prevention and maintenance access. |
| 5 |
Plug Valve |
Pipeline isolation, contaminated hydrocarbon service, pig launcher systems and applications requiring low leakage and compact installation; commonly used in Class 150–1500. |
Carbon or low-alloy steel body; stainless, nickel-alloy or corrosion-resistant overlay for plug, stem and internal wetted surfaces when required by the process fluid. |
Lubricated and sleeved designs require qualification of the plug, stem, seal system and any internal coating for sour exposure. Material hardness limits remain applicable to pressure-retaining parts. |
Body: commonly screened around 0 to +60°C for carbon/low-alloy sour service. Seal and lubricant temperature limits can be lower than the body limit. |
Lubricants, sealants and sleeves must be compatible with H₂S, hydrocarbons, pressure cycling and decompression. PTFE-based components require grade-specific verification. |
Review operating torque, anti-blowout stem design, cavity pressure management, fire-safe performance and emissions testing. |
| 6 |
High-Performance Butterfly Valve |
Large-diameter isolation and control in process plants, water injection, gas treatment and utility headers; commonly used in Class 150–600, with higher classes available for selected designs. |
Carbon steel, stainless steel or duplex body depending corrosion conditions; stainless, duplex or nickel-alloy disc and shaft options for H₂S-bearing fluids. |
Disc, shaft, pins, retainers and body materials must be checked individually. Shaft and pin hardness, galvanic couples and crevice corrosion are important in wet sour service. |
Body: material-dependent; carbon-steel sour-service screening is often limited to approximately 0 to +60°C. Seat and liner limits may govern the actual operating range. |
Metal seats support higher temperatures and fire-safe service. PTFE, reinforced PTFE and elastomer seats require individual temperature, decompression and H₂S compatibility checks. |
Confirm bidirectional shutoff, disc clearance, torque margin, shaft retention, fugitive emissions and allowable velocity. |
| 7 |
Needle Valve |
Instrumentation isolation, pressure gauges, chemical injection, sampling and small-bore high-pressure control; commonly used in Class 600–6000. |
316L stainless steel, duplex stainless steel or nickel alloys are commonly considered for wetted parts; carbon steel may be used only when specifically qualified for the service. |
Small-bore components can be highly susceptible to hardness-related cracking. Verify cold-work condition, heat treatment, thread condition and material certification under MR0175/ISO 15156. |
Alloy-dependent: approximately −46 to +150°C may be a preliminary range for suitable stainless or duplex designs, but the actual limit depends on grade, pressure and environment. |
Use metal-to-metal or qualified polymer seals. Packing, stem tip and bonnet materials should be reviewed for H₂S, chloride and pressure cycling. |
Specify connection type, pressure rating, anti-galling treatment, panel-mount arrangement and minimum passage size. |
| 8 |
Subsea or Extended-Bonnet Gate/Ball Valve |
Subsea production systems, manifolds, injection lines and locations requiring remote operation or thermal separation; pressure classes are project-specific. |
Qualified carbon/low-alloy steel or corrosion-resistant alloy pressure boundary; duplex and nickel alloys may be used for selected wetted components. |
Material qualification must cover pressure, temperature, H₂S exposure, seawater, cathodic protection, welds, fasteners and long-term corrosion-fatigue performance. |
Temperature is governed by both the process fluid and the external seawater environment. Do not assign a generic MR0175 limit without project-specific qualification. |
Use qualified seals for external seawater, internal H₂S and rapid gas decompression. Hydraulic and electrical actuation materials require separate compatibility review. |
Confirm subsea qualification, water-depth rating, intervention philosophy, actuator reliability, corrosion allowance and inspection access. |