API · ASME · DIN · EN standard industrial valves

Bellow-Seal Control Valves

Bellow-seal control valves seal the stem with a welded metal bellows instead of a packing box, removing the dynamic leak path entirely for hazardous, toxic or fugitive-emission service — the choice where even zero-leak packing is not acceptable. The range covers sizes from 1/4 inch through 4 inch NPS at pressure ratings through ASME Class 2500, in SA 105 / SA 182-F22 / F91 / F92 / F316 forged materials, built to MSS SP-117 for bellows longevity, with a 6-ply nickel-chromium alloy welded bellows stem seal, Y-pattern, angle-pattern and T-pattern body styles, solid cobalt-chrome seats and discs, and electric, pneumatic or hydraulic actuation with locking devices, single or dual limit switches, stem shrouds, position indicators and leak-off ports as accessories. Every bellows assembly is helium mass-spectrometer tested for zero leakage before shell and seat testing, beyond the Method 21 fugitive-emissions protocol. Selection turns on the emissions containment requirement, the size/pressure point against the forged-body ratings, and the body pattern.

Part of the Control Valves family

Last updated: 2026-11

Family specifications

size range 1/4 inch through 4 inch NPS
pressure class Through ASME Class 2500
body materials SA 105, SA 182-F22, SA 182-F91, SA 182-F92, SA 182-F316
design standards MSS SP-117
testing standards Helium gas mass spectrometer zero-leakage test on every bellows assembly, beyond Method 21 protocol
bellows seal 6-ply nickel-chromium alloy welded bellows stem seal
body styles Y-pattern, Angle-pattern, T-pattern
seat disc materials Solid cobalt-chrome seats and discs
accessories Actuators – Electric, Pneumatic or Hydraulic, Locking Devices – Open, Closed or Both, Limit Switches – Single or Dual, Stem Shroud, Position Indicator, Leak-Off Port
seal mechanism metallic bellows welded to the stem and bonnet forms a hermetic primary seal; the bellows flexes with stem movement instead of sliding through packing
secondary sealing backup gland packing (graphite or PTFE) provided in addition to the welded bellows
bellows material options stainless steel, nickel-chromium alloy, special alloys
bellows cycle life on the order of 10,000+ operating cycles before bellows replacement
emission compliance EPA Method 21, TA-Luft, ISO 15848
emission certification TA-Luft (VDI 2440) and ISO 15848-1 Class AH low fugitive emission compliance
control trim options heavy guided plug, bellows sealed zero-leakage trim, and Y-pattern low pressure-drop bodies
typical services toxic and hazardous chemical media, steam systems and feedwater circuits, thermal oil, vacuum service, cryogenic fluids with suitable bellows material
maintenance profile no regular packing adjustment required; the metal bellows maintains sealing integrity without adjustment
bellows life cycle control duty under standard control valve conditions the metal bellows life can commonly exceed 5,000,000 cycles (stroke motion between defined travel positions)
iso15848 cycle test record bellows design successfully tested over 100,000 cycles according to ISO 15848 with leakage rate tightness class AH per ISO 15848 (helium test)
bellows base material 316ti standard bellows material 316Ti stainless steel, with various special alloys available for corrosive applications
bellows cavity test port threaded test connection between the bellows and the packing allows cavity pressure monitoring before external leakage is visible
bellows retrofit and jacket option modular bellows design retrofits easily into existing valves when new stricter emissions requirements apply; optional full body heating jacket prevents crystalline deposits in the folds of the metal bellows
bellows zero hysteresis metal bellows stem sealing introduces no hysteresis: no deviations from the valve characteristic
emission standard coverage bellows emission limits specified per TA Luft, ISO 15848 and ANSI/FCI 91-1-2010
hazardous duty size class envelope hazardous-chemical bellows seal globe control valves in sizes 1 to 12 inch (DN 25 to DN 300); end connections CL150, CL300, CL600, PN16, PN25, PN40; cast body materials A352 LCC carbon steel, A351 CF8M stainless steel, A494 M35-1 nickel-copper, CW12MW nickel-chrome-moly-tungsten and CY40 nickel-chrome-iron
bellows ply construction two or three ply UNS N10276 bellows with UNS N10276 end rings; open bellows design allows examination and prevents bellows damage from trapped corrosion products
open bellows maintenance design open bellows design gives ease of examination and maintenance with no bellows damage due to trapped corrosion products
control trim stage options contoured, single-stage and multi-stage cage trim options covering noisy gas and flashing/cavitating liquid duties
bellows cycle guarantee gest bellows guaranteed for at least 100,000 open/close/open cycles per the Euro Chlor GEST 17/492 requirement
hazardous duty flow characteristics flow characteristics linear, equal percentage and specials
isa face to face series face-to-face dimensions per ISA-75.08.01-2002: Class 150 series 37, Class 300 series 38, Class 600 series 39
auxiliary packing design spring-loaded five-ring PTFE chevron auxiliary stuffing box packing set requiring no routine maintenance; leak detection tapping to the inter space between bellows seal and auxiliary gland available as an option
trim seat hardfacing replaceable trim with hard-faced (stellited) sealing surface as standard, soft seal seat available as option; plug pinned to stem to ensure repeatable flow control
testing requirements hazardous duty all testing performed to the requirements of the latest Euro Chlor GEST 17/492, ASME B16.34 and ANSI/FCI 70.2
bellows welding process metallic bellows welded between bonnet and stem by automatic roll welding technology, giving zero leakage at the stem sealing area during operation
large size stabilizer device triangular stabilizing (anti-vibration) device installed for sizes DN150 and above to protect internal components from vibration, reduce noise and improve structural strength
disc configuration options bs disc configurations selected per operating condition, including regulating disc, globe-check disc and soft-seal disc options
mark74 lab cycle life in lab tests, the Mark 74 exceeded 2 million cycles with no bellows failure
mark74 short stroke bellows a valve stroke that is just a fraction of that of other rising stem valves
mark74 backup packing chamber A secondary chamber of multiple packing rings provides extra leakage protection
mark74 bellows monitoring port a gauge can be mounted to verify bellows performance
mark74 approvals envelope 1/2′′ – 2′′, ATEX Certified
mark74 hazardous media scope reducing the risks associated with toxic, corrosive, explosive and high temperature fluids
bellows double seal design DIN/EN bellows executions use a double seal design: the welded bellows is the primary stem seal and backup stem packing contains the leak if the bellows fails
din bellows multiply welded DIN/EN bellows executions feature a formed multi-ply bellows welded to the stem and to the bottom of the bonnet, creating a hermetic seal or impermeable barrier
gas service ptfe soft seat option a PTFE soft-seat option is offered for gas media to improve tightness
cone seal up to 400c a cone seal seat is used at temperatures up to 400°C to achieve zero leakage sealing performance
din execution design standard DIN bellows globe executions are designed to EN 13709
din execution face to face series face-to-face dimensions per EN 558-1
din execution flange standards end flanges per EN 1092-1; butt-welding ends per EN 12627
din execution testing standard inspection and test per EN 12266-1
din execution size range size range DN15-DN400 for the DIN bellows globe execution
din execution pressure rating pressure ratings PN16, PN25 and PN40
din execution temperature range temperature range -10°C to 400°C
din execution body materials GS-C25 cast carbon steel body execution
din execution body material options cast steel, stainless steel, special alloy, cast iron and ductile iron body options available for the DIN bellows globe line
din3356 design execution a cast iron bellows-seal globe execution is built to DIN 3356
din3202 f1 face to face the DIN 3356 cast iron execution uses face-to-face dimensions per DIN 3202-F1
din2532 2533 flange standard the DIN 3356 cast iron execution uses flange ends per DIN 2532/DIN 2533
din execution cast iron envelope cast iron GG25 DIN 3356 execution envelope: DN15-DN250, PN16, handwheel operated
din execution bellows material options 316Ti / 321 stainless steel bellows material options in the DIN 3356 GS-C25 execution
din execution stem materials stem material options SS420 / SS431
din execution seat materials seat with stainless steel overlay
din execution wide temperature range operating temperature -29°C to 400°C for the DIN 3356 GS-C25 PN16 execution
din execution zero visible leakage leakage class: zero visible leakage at the stem seal
din execution actuation handwheel operation standard; electric and pneumatic actuation optional
din en leakage rate class a EN bellows executions are tested to leakage rate A per EN 12266-1 with face-to-face per EN 558-1 series 1 (F1) and EN 1092-1 flanges
din execution bellows material tistabilized Ti-stabilized 316 grade X6CrNiMoTi17-12-2 bellows with 1.4021 (X20Cr13) stem and graphite packing rings in the EN 558-1 series 1 (F1) steel execution
din execution steel body trim materials steel execution: body in 1.0619 (GP240GH), disc/cone in 1.4021 (X20Cr13 + QT), stem 1.4021 (X20Cr13), stainless steel seat, graphite packing rings
din execution cast iron variant PN16 cast iron variant of the same bellows globe line: body EN-GJL-250 grey cast iron with EN 1092-2 flanges, same 1.4021 trim and X6CrNiMoTi17-12-2 bellows, graphite packing
moq 1 set
lead time 15 to 30 days
warranty 18 months

Ordering & documentation

Documents

Ask for the documentation set with the inquiry — typical items (material certificates, test reports to the listed inspection standard, dimensional drawings) are confirmed and supplied with the quotation.

Quotation

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Sample & supply

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Storage & shipping

Store valves with seats and seals protected from UV, ozone and deformation, and keep end-face protectors on until installation; storage limits and shipping arrangements for the selected materials are confirmed at quotation.

Frequently asked questions

What standards govern the design and testing of bellow-seal control valves?

The published specification for this family lists MSS SP-117 as the design standards. Testing follows Helium gas mass spectrometer zero-leakage test on every bellows assembly, beyond Method 21 protocol.

What sizes and pressure ratings are available for bellow-seal control valves?

The published size range is 1/4 inch through 4 inch NPS, and the published pressure ratings are Through ASME Class 2500. Availability of a specific size and rating is confirmed at quotation.

What materials are bellow-seal control valves available in?

The published specification lists body materials: SA 105, SA 182-F22, SA 182-F91, SA 182-F92, SA 182-F316. Material availability for a specific size and rating is confirmed at quotation.

What should a quotation inquiry for bellow-seal control valves include?

The governing standard and class, nominal size, body and seat materials, the service medium with temperature, and the destination — anything missing is confirmed during quotation.

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