Welch Vacuum Pump Spare Parts
Spare parts for Welch laboratory vacuum pumps. DuoSeal 1376/1397/1400/1402/1405, CRVpro direct-drive rotary vane, ChemStar oil and dry, DryFast PTFE diaphragm, WOB-L oil-free piston — service kits, vanes, diaphragms, oils, and rebuild parts for laboratory and pharma applications.
Laboratory Vacuum Specialist Since 1904
Welch was founded in 1904 in Skokie, Illinois as part of the W.M. Welch Manufacturing Co. (later Sargent-Welch Scientific). The vacuum division was spun off as Welch Vacuum Technology in 1990, then absorbed by Thomas Industries, Gardner Denver, and finally Ingersoll Rand following the February 2020 merger. Welch (US, Niles IL) plus Ilmvac GmbH (Germany) operate as one global Welch Vacuum brand within Ingersoll Rand's Precision and Science Technologies segment.
Welch's flagship DuoSeal 1402 belt-driven two-stage rotary vane was introduced in the 1940s and is still in production — making it one of the longest continuously-produced laboratory vacuum pumps in existence. We stock service kits, oils, vanes, exhaust valve plates, V-belts, and diaphragms for the entire current Welch range, plus the legacy DuoSeal models that remain in service in universities, pharma labs, and freeze-drying applications across the UK.
Welch Pump Ranges We Supply Parts For
We stock spare parts for every Welch vacuum pump series — from compact laboratory pumps to large industrial systems.
DuoSeal (belt-driven two-stage rotary vane)
Belt-driven two-stage oil-sealed rotary vane pumps — the laboratory standard since the 1940s
CRVpro (direct-drive rotary vane)
Direct-drive two-stage rotary vane pumps for general lab vacuum (1.8–52.5 cfm)
ChemStar (chemical-duty rotary vane)
Oil-sealed two-stage rotary vane pumps optimised for chemical and solvent duty
ChemStar Dry (dry rotary vane)
Dry rotary vane pumps for chemistry where oil contamination must be avoided
DryFast / DryFast Ultra (PTFE diaphragm)
PTFE diaphragm pumps for chemical-resistant vacuum filtration and rotovap duty
WOB-L (oil-free piston)
Oil-free piston vacuum pumps and compressors for clean lab use
Standard / Mini Diaphragm
Compact diaphragm pumps for low-flow lab duty
Don't see your pump model listed? We also supply parts for discontinued and legacy Welch models. Contact us for availability.
Complete Range of Welch Spare Parts
From routine service kits to specialist components — we stock everything needed to maintain and repair Welch vacuum pumps.
V-Belts
Drive belts and tensioners for belt-driven DuoSeal models
Common Questions About Welch Parts
Everything you need to know about sourcing Welch vacuum pump spare parts from one of the UK's most comprehensive independent stockholders.
Speak to an ExpertWe stock parts for the complete Welch range — DuoSeal belt-driven two-stage rotary vane (1374, 1376, 1397, 1400, 1402, 1405), CRVpro direct-drive (CRVpro 2 through CRVpro 65), ChemStar and ChemStar Dry chemical-duty rotary vane, DryFast PTFE diaphragm, and WOB-L oil-free piston pumps. Inventory includes service kits, vanes, diaphragms, V-belts, oils, exhaust valve kits, and filters.
Yes — the 1402K-06 major repair kit (vanes, exhaust valves, gaskets, seals) for the Welch 1402 belt-driven DuoSeal is a continuous stock item, alongside equivalent major and minor kits for the other DuoSeal models (1374, 1376, 1397, 1400, 1405). Both genuine Welch and OEM-equivalent kits are available.
Oil discoloration is the most common indicator of a DuoSeal needing service — it's caused by thermal breakdown, condensable vapour absorption, or oxidation. Welch's manual specifies oil change every ~3,000 hours or whenever the oil shows discoloration. Operating a DuoSeal continuously above 1 Torr causes excessive oil spraying and premature failure; if your duty cycle requires higher pressures, talk to us about a different pump configuration.
Yes. The DuoSeal 1402 has been in production since the 1940s and we hold continuous stock for the older belt-driven 1374, 1376, 1380, 1399, and 1402 models. Drive belts, tensioners, vanes, exhaust valve plates, oils, and major repair kits are all available — these are some of the most third-party-supported pumps in the world thanks to their longevity.
Yes. We stock replacement PTFE diaphragm and valve plate sets for the DryFast and DryFast Ultra range (2034, 2042, 2052, 2046). Diaphragm rupture is the most common chemistry-pump failure mode — keeping a spare diaphragm set on hand is recommended for any chemistry lab.
DuoSeal pumps are belt-driven (motor and pump on a common base, connected by a V-belt). CRVpro pumps are direct-drive (motor and pump on a common shaft, more compact, lower noise). Both are two-stage oil-sealed rotary vane reaching ~1.5–2×10⁻³ Torr. Direct-drive CRVpros are increasingly the modern choice; belt-driven DuoSeals remain popular where their established reliability and serviceability are valued.
Yes — DuoSeal Direct-Torr oil, Welch Gold pump oil for higher-temperature duty, ChemStar PFPE for chemical-resistant pumps, and recommended OEM-equivalent alternatives. Available in 1L, 4L, and 20L containers.
Yes — fully rebuilt Welch DuoSeal and CRVpro pumps are widely used in academic and commercial labs. We can supply rebuild kits if you have an in-house service capability, or refer you to refurbishers if you need a complete exchange unit.
All in-stock Welch parts are available on a next-day UK mainland basis. The DuoSeal 1402K-06, common CRVpro service kits, and DryFast diaphragms are continuous stock items.
Need Welch Spare Parts?
Send us your pump model or part number and we'll come back quickly with price and availability — next-day UK mainland delivery on stocked items.
We Also Supply Parts For
In addition to Welch, we stock spare parts for all major vacuum pump manufacturers.