Flat seals

A flat seal closes flange and threaded joints where an O-ring cannot be fitted. It seals through deformation on tightening. Below are 64 Hansa Flex BOERD and FD sizes.

Complete size range — 64

The table lists 64 sizes. Start typing a part number or size to filter the list.

64
Part number
BOERD DI DN15 PN16
BOERD DI DN20 PN16
BOERD DI DN25 PN16
BOERD DI DN32 PN16
BOERD DI DN40 PN16
BOERD DI DN50 PN16
BOERD DI DN65 PN16
BOERD DI DN100 PN16
BOERD DI DN125 PN16
BOERD DI DN150 PN16
BOERD DI DN175 PN10
BOERD DI DN200 PN16
BOERD DI DN250 PN16
BOERD DI DN300 PN16
BOERD DI DN350 PN16
BOERD DI DN400 PN16
BOERD DI DN450 PN16
FD DN10 PN40 C4400
FD 15-11-1 C4400
FD DN15 PN40 C4400
FD DN20 PN40 C4400
FD DN25 PN40 C4400
FD DN32 PN16 C4400
FD DN40 PN40 C4400
FD 41-33.2-2 C4400
FD DN50 PN40 C4400
FD 55-41-1.5 C4400
FD 60-20-3 C4400
FD DN65 PN40 C4400
FD 70-45-3 C4400
FD DN80 PN40 C4400
FD 82-66-1 C4400
FD 85-70-0.5 C4400
FD 90-40-3 C4400
FD 100-50-3 C4400
FD DN100 PN16 C4400
FD 105-65-3 C4400
FD 110-75-2 C4400
FD 110-85-3 C4400
FD DN125 PN16 C4400
FD 140-121-1.5 C44
FD 140-121-1.5 C4400
FD DN150 PN16 C4400
FD DN150 PN40 C4400
FD 190-125-3 C4400
FD DN200 PN16 C4400
FD 220-150-3 C4400
FD DN250 PN16 C4400
FD 270-200-3 C4400
FD 280-162-2 C4400
FD 310-295-0.5 C44
FD 310-295-0.5 C4400
FD 320-250-3 C4400
FD 380-300-3 C4400
FD 380-325-2 C4400
FD 485-400-3 C4400
FD DN500 PN10 C4400
FD 540-490-3 C4400
FD 570-500-3 C4400
FD 590-500-3 C4400
FD 680-600-3 C4400
FD 800-670-3 C4400
FD 1080-1010-3 C44
FD 1080-1010-3 C4400

How to select the size

The key dimensions are nominal bore DN and thickness. For DIN/EN flanges the bolt circle and hole diameter also matter.

Thickness follows surface roughness: the rougher the face, the thicker the gasket.

Materials

The material is chosen by medium and temperature, not by price:

  • NBR — the standard for mineral oil, −30…+100 °C. Most common and least expensive.
  • FKM (Viton) — up to +200 °C, aggressive media, brake fluid. Three to five times the price of NBR.
  • PU (polyurethane) — high pressure and abrasion, but not above +80 °C.
  • PTFE — chemicals, very low friction, but poor under compression without support.
  • EPDM — water, steam, glycol-based brake fluid. Not compatible with oil.

Common fitting mistakes

Three mistakes that make a new seal leak within a day:

  1. Damaged lip during fitting. The seal is pushed over threads or splines without a sleeve — the lip is cut and you cannot see it.
  2. Measuring a worn part. The old ring has lost its shape, so the new size does not seat in the groove.
  3. No back-up ring. Above 160 bar the seal extrudes into the gap.

Frequently asked questions

What is the difference between BOERD and FD?
BOERD is a DIN flange gasket with bolt holes. FD is a flat-profile sealing ring without bolt holes.

Can a gasket be cut on site?
For an emergency repair, yes. For regular service use a factory part — thickness and material are consistent.

Which materials are used?
NBR, FKM, PTFE and compressed fibre sheet for different media.

Flat seals for static sealing of flanges, housings and threaded connections where an O-ring does not fit. NBR, FKM, EPDM and PTFE in thicknesses from 1 to 5 mm, cut to the original shape. Send the old seal, a drawing or the part number and we confirm material and dimensions within 24 hours.

Showing 1–16 of 64 results

Frequently Asked Questions

Do you supply genuine parts or Chinese equivalents?

Genuine parts are our main business. If you need a lower-cost option, we can also look for a Chinese-made equivalent with the same mounting dimensions and ratings.

What is the lead time?

It depends on the supplier. If the factory has stock or produces in China, we ship quickly. A factory order that must be manufactured or shipped from abroad takes longer. We confirm the exact date in your quote.

How do I place an order?

Send the part number, a photo of the nameplate, or the machine model. We confirm availability and price within 24 hours.

What are the payment and shipping terms?

EXW by default. 20-50% prepayment, balance before shipment. We can work with your freight forwarder.

What are flat seals used for?

Static sealing of flanges, housings and threaded connections where an O-ring is not suitable.

What materials do you supply?

NBR, FKM, EPDM and PTFE in thicknesses from 1 mm to 5 mm.

Need a price or an equivalent?

Send the part number or a photo — we will match it and reply within 24 hours.

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