Shaft seal kit for close-coupled liquid ring vacuum pumps in meat and poultry plants: rotary seal, V-ring, counter ring and impeller gap
Wear-part kit for close-coupled liquid ring vacuum pumps on wet meat and poultry duties · rotary shaft seal with counter ring, V-ring, radial shaft seal, control-disc seal and the impeller gap set on reassembly
In a close-coupled liquid ring pump the impeller sits on the extended motor shaft, so the only barrier between the ring liquid in the pump housing and the motor bearings is a small shaft seal set. On meat and poultry duties the gas drawn in can carry water, blood, brine and small solids, which end up in the ring liquid that wets that seal. The seal set is bought as a kit, and fitting it is not only a matter of swapping parts: on reassembly the V-ring is set to a measured distance and the impeller is pressed back to a clearance gap of a fraction of a millimetre.
Shaft seal kits and their fitting for close-coupled (motor-shaft) liquid ring vacuum pumps used on wet duties in meat and poultry plants: rotary mechanical seal with counter ring and O-ring, V-ring, radial shaft seal, control-disc seal, valve plate and tolerance ring, with grease and fitting dimensions. Choosing a vacuum pump type is covered on the Vacuum pump page; complete liquid ring and booster packages on the Packaged vacuum pump system and Liquid ring vacuum system pages; mechanical seals for centrifugal pumps, mixers and agitators, with face materials and piping plans, on the Mechanical seal page; lip seals and gaskets for hygienic product-contact equipment are outside this page.
CNFX editorial research · Sources checked October 12, 2026 · 4 sources
Why the seal sees blood, brine and solids on a meat plant pump
Atlas Copco's poultry-industry page describes evisceration as a wet process done under vacuum with a liquid ring pump that handles water, blood and small parts, and names holding good pressure, clean-up and internal contamination as the concerns that lead it to recommend liquid ring pumps for marinating and tumbling. [3]
The same page describes offal transport through a piping network to a collection area as a wet and dirty process and lists its AWS and AWC liquid ring pumps for that duty. [3] Editorial note: on these duties the seal faces run in ring liquid that also carries what the process sends down the suction line, so the questions for a seal kit are its face and elastomer materials and how often it is changed, not only its size.
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What one maker's kit contains, and the V-ring and impeller gaps set on reassembly
Gardner Denver's repair instructions for its L-BV2 close-coupled liquid ring pumps (types 2BV2060, 2BV2061, 2BV2070 and 2BV2071) list a spare parts kit and the dimensions to restore when it is fitted. [1]
The instructions warn that the rotor may be damaged while the rotary seal is taken off, that the counter ring may have to be destroyed to remove it, and that parts marked for replacement on disassembly cannot be reused. [1] Because the pump is loaded from the ventilation side in operation, the gap is checked with the unit standing on its shaft end and pressure applied from that side. [1]
The listed grease, UNIREX N3 or an alternative to DIN 51825-K3N, is for standard operating conditions only; for use in the food production industry the instructions say to ask the manufacturer for the grease type. [1] In the United States, lubricants with incidental food contact on food-processing machinery fall under 21 CFR 178.3570, which lists permitted substances with limits such as mineral oil at no more than 10 parts per million added to food, and requires that the amount used is the minimum needed for the technical effect. [4]
Item
Published detail
Kit contents
Feather key (006), V-ring (033), rotary seal (035), spiral locking pin (037), tolerance ring (048), valve plate (050), catch plate (051), control-disc seal (057), O-ring (058), screw (150) [1]
Rotary seal
Counter ring with O-ring pushed into the pump housing, then the rotating seal and washer slipped on and compressed by the impeller feather key; parts brushed with flushing liquid first [1]
Motor-side seals
Radial shaft seal (452) in the ventilation-side end plate, greased on fitting [1]
V-ring position
Measurement X from V-ring to sealing ring: 8.2 −0.5 mm on 2BV2060/2061/2070; 9.7 −0.5 mm on 2BV2071 [1]
Impeller clearance gap
0.15 ± 0.05 mm standard version; 0.15 +0.05 mm stainless steel version; measured over Ø 82 mm (2BV206.) or Ø 108 mm (2BV207.) [1]
Tolerance ring
Greased on fitting; if the impeller is pressed past the required gap, it has to be removed and refitted with a new tolerance ring [1]
Order the kit by the pump's full type number and serial number, and ask for the food-plant grease the maker approves for the tolerance ring and radial shaft seal.
03
Pressure, vacuum, speed and material limits printed on an elastomer bellows seal datasheet
Where a plain-shaft pump uses a standard seal instead of a maker's kit part, the seal maker's datasheet sets the limits. EagleBurgmann's eMG1 elastomer bellows seal is one published example; its figures are stated as guide values. [2]
The datasheet lists food and beverage among the recommended industries and FDA among the approvals available depending on type and material combination, to be confirmed on enquiry. [2] Editorial calculation: at an assumed shaft speed of 3,000 rpm, the 10 m/s sliding-velocity limit is reached at a face diameter of 10 / (π × 50 rev/s) ≈ 0.064 m, about 64 mm. [2] Editorial note: the vacuum figure matters on a vacuum pump, so ask whether the seat in the replacement seal is locked in its housing.
Faces carbon graphite, silicon carbide or tungsten carbide; elastomers NBR, EPDM, FKM or HNBR; metal parts CrNiMo steel or Hastelloy C-4 [2]
Seats
G6 and G60 to EN 12756, with G4, G9 and G50 alternatives [2]
Ask for the seal's vacuum rating with and without seat locking, the elastomer grade and its food-contact approval, and the face pair offered for ring liquid carrying solids.
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What to send when ordering a seal kit
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Pump: [maker; full type number; serial number; standard or stainless version]
Duty: [evisceration / tumbling / offal transport; ring liquid; once-through or recirculated]
Seal: [kit or EN 12756 seal; faces; elastomer; vacuum rating; seat locking]
Grease: [food-plant grade for tolerance ring and radial shaft seal]
Fitting: [V-ring measurement X; impeller clearance gap; new tolerance ring]
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
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Compiled and source-reviewed by the CNFX editorial team.
Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review
· Page last updated 13 October 2026
Buyer questions
What impeller gap is set after changing the seal on an L-BV2 pump?
0.15 ± 0.05 mm on the standard version, checked with pressure applied from the ventilation side. [1]
Can a mechanical seal on a vacuum pump hold vacuum?
EagleBurgmann's eMG1 datasheet admits vacuum to 0.5 bar, or up to 1 bar with seat locking. [2]
Why are liquid ring pumps used on wet poultry duties?
Atlas Copco states they handle the water, blood and small parts from evisceration and recommends them for tumbling because of pressure holding, clean-up and contamination concerns. [3]
Sources and what still needs a direct check
Sources checked 2026-10-12. A pump maker's repair instructions give the kit and fitting dimensions; a seal maker's datasheet gives standard seal limits; a vacuum pump maker's industry page describes the wet poultry duties; the US Code of Federal Regulations gives the incidental-contact lubricant rule.
