Rubber Bellows Mechanical Seals

Rubber (elastomer) bellows seals for water, utility and light process pumps, metric and inch. The models below are the standard ones in our catalog; we build most other rubber bellows seals too.

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Not on the list? We build most rubber bellows seals of any brand, in standard or special sizes: send the seal part number, a drawing or the old seal. All are equivalents, not sold as genuine OEM parts.

Rubber bellows seal head with ceramic seat

We are the manufacturer, not a reseller: faces, bellows and springs are matched to your duty and built in-house at quantities that suit a distributor, an OEM or a maintenance department.

Metric & inchstandard shaft sizes in both

Any face paircarbon, ceramic, SiC or tungsten carbide

NBR, EPDM, Vitonbellows elastomer to suit the fluid

Catalog

Rubber bellows seals in our catalog

Pick the model by its shape on the drawing and its size range; the drawings and dimension tables follow below.

Model	Standard sizes (d1)	Pressure	Speed	Temperature
WM 101	16 – 35 mm	≤ 0.4 MPa	≤ 3 m/s	-20 to +80 °C
WM 102	14 – 20 mm	≤ 0.3 MPa	≤ 3 m/s	-20 to +80 °C
WM 103	10 – 18 mm	≤ 0.8 MPa	≤ 5 m/s	-30 to +200 °C
WM 104	9 – 45 mm	≤ 0.4 MPa	≤ 5 m/s	-30 to +200 °C
WM 108	9 – 55 mm	≤ 1 MPa	≤ 10 m/s	-30 to +200 °C
WM 155/155B	10 – 40 mm	≤ 1 MPa	≤ 10 m/s	-30 to +200 °C
WM 156	On request	≤ 0.5 MPa	≤ 10 m/s	-30 to +200 °C
WM 166/E	5/16" – 1" · 3/8" – 1"	≤ 1 MPa	≤ 15 m/s	-30 to +200 °C
WM 166T	3/8" – 3" · 12 – 55 mm	≤ 0.5 MPa	≤ 10 m/s	-30 to +200 °C
WM 70	10 – 16 mm	≤ 0.6 MPa	≤ 10 m/s	-30 to +200 °C
WM T1	5/8" – 3"	≤ 2.8 MPa	≤ 13 m/s	-30 to +200 °C
WM T2	On request	≤ 2.8 MPa	≤ 13 m/s	-30 to +200 °C
WM FBD	16 – 120 mm · 5/8" – 2 1/2"	≤ 1 MPa	≤ 12 m/s	-30 to +200 °C
WM 560A/B	10 – 55 mm · 3/8" – 3"	≤ 1 MPa	≤ 12 m/s	-30 to +200 °C
WM BIA	14 – 70 mm	≤ 1 MPa	≤ 10 m/s	-30 to +200 °C
WM 20	3/8" – 3" · 10 – 75 mm	≤ 0.8 MPa	≤ 10 m/s	-20 to +150 °C
WM 21	1/2" – 3"	≤ 0.8 MPa	≤ 10 m/s	-20 to +150 °C
WM 24	12 – 75 mm	≤ 0.8 MPa	≤ 10 m/s	-20 to +150 °C
WM 301	6 – 70 mm	≤ 0.6 MPa	≤ 10 m/s	-30 to +200 °C
WM 960	14 – 65 mm	≤ 1.2 MPa	≤ 15 m/s	-30 to +200 °C
WM 2100	10 – 100 mm · 1" – 3 7/8"	≤ 0.2 MPa	≤ 15 m/s	-30 to +200 °C
WM 502	14 – 100 mm	≤ 1.2 MPa	≤ 12 m/s	-30 to +200 °C

Limits as printed in our catalog for each model; the real limit depends on the face pair, elastomer and fluid.

Drawings & dimensions

Drawings and dimension tables

Dimensions in mm unless a table says inches. Inch sizes are named by the nominal shaft size in inches; d1 gives the same size in mm. Letters match the section drawing. Standard sizes shown; other sizes are built from a drawing or the old seal.

Catalog model

WM 101

Pressure: ≤ 0.4 MPa
Speed: ≤ 3 m/s
Temperature: -20 to +80 °C

Rotary ring: Ceramic
Stationary ring: Plastic carbon
Secondary seals: NBR, Viton
Spring and retainer: Stainless steel, copper

Model	d1 (mm)	d3	d4	d7	l1	l3	l6
WM101-16	16	30	23	35	35	27	5.5
WM101-25	25	42.5	29.5	41	40	31	7
WM101-35	35	54	41	52	45	36	7

Catalog model

WM 102

Pressure: ≤ 0.3 MPa
Speed: ≤ 3 m/s
Temperature: -20 to +80 °C

Rotary ring: Ceramic
Stationary ring: Plastic carbon
Secondary seals: NBR, Viton
Spring and retainer: Stainless steel, copper

Model	d1 (mm)	d3	d7	l1	l3	l6	l7
WM102-14	14	33	35	24.5	17.5	5	13
WM102-18	18	37	40	24.5	17.5	5	13
WM102-20	20	38	40	25	18	5	15

Catalog model

WM 103

Pressure: ≤ 0.8 MPa
Speed: ≤ 5 m/s
Temperature: -30 to +200 °C

Rotary ring: Ceramic
Stationary ring: Plastic carbon
Secondary seals: NBR, Viton
Spring and retainer: Stainless steel, copper

Model	d1 (mm)	d7	l1	l3
WM103-10	10	25	20.5	5
WM103-12	12	26	20.5	5.5
WM103-14	14	30	20.5	7
WM103-17	17	35	20.5	7
WM103-18	18	35	20.5	7

Catalog model

WM 104

Pressure: ≤ 0.4 MPa
Speed: ≤ 5 m/s
Temperature: -30 to +200 °C

Rotary ring: Ceramic
Stationary ring: Plastic carbon
Secondary seals: NBR, Viton
Spring and retainer: Stainless steel, copper

Model	d1 (mm)	d7	l1	l3
WM104-9	9	22	20	5.5
WM104-10	10	22	20	5.5
WM104-11	11	24	20	5.5
WM104-12	12	24	20	5.5
WM104-14	14	26	25	7
WM104-15	15	28	25	7
WM104-16	16	28	25	7
WM104-17	17	34	25	7
WM104-18	18	34	25	7
WM104-19	19	36	25	7
WM104-20	20	36	25	7
WM104-22	22	38	25	7
WM104-25	25	41	37	9
WM104-30	30	46	37	9
WM104-35	35	51	37	9
WM104-40	40	60	40	10.5
WM104-45	45	65	40	10.5

Catalog model

WM 108

Pressure: ≤ 1 MPa
Speed: ≤ 10 m/s
Temperature: -30 to +200 °C

Rotary ring: Plastic carbon, carbon, SiC, tungsten carbide
Stationary ring: Ceramic, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and metal parts: 304 stainless, 316 stainless

Model	d1 (mm)	d3	d7	l1	l3
WM108-9	9	20	21	20	5
WM108-10	10	20	21	20	5
WM108-11	11	22	23	20	5
WM108-12	12	22	23	20	5
WM108-14	14	24.5	25	25	5
WM108-15	15	26.5	27	25	5
WM108-16	16	26.5	27	25	5
WM108-17	17	32	33	25	5
WM108-18	18	32	33	25	5
WM108-19	19	34	35	25	7
WM108-20	20	34	35	25	7
WM108-22	22	36	37	28	7
WM108-25	25	39	40	32	8
WM108-28	28	42	43	35	8
WM108-30	30	44	45	35	8
WM108-35	35	49	50	37	8
WM108-40	40	56	58	40	8
WM108-45	45	61	63	40	9
WM108-50	50	67	70	45	9
WM108-55	55	72	75	45	9

Catalog model

WM 155/155B

Pressure: ≤ 1 MPa
Speed: ≤ 10 m/s
Temperature: -30 to +200 °C

Rotary ring: Plastic carbon, carbon, SiC, tungsten carbide
Stationary ring: Ceramic, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and metal parts: 304 stainless, 316 stainless

WM155 · Metric sizes

Model	d1 (mm)	d3	d7	l1	l3
WM155-10	10	20	18.1	20.5	5.5
WM155-11	11	22	20.6	23.5	5.5
WM155-12	12	22	20.6	23.5	5.5
WM155-13	13	25	23.1	28	6
WM155-14	14	25	23.1	28	6
WM155-15	15	29	26.9	30	7
WM155-16	16	29	26.9	30	7
WM155-17	17	29	26.9	30	7
WM155-18	18	33	30.9	32	8
WM155-19	19	33	30.9	33	8
WM155-20	20	33	30.9	33	8
WM155-21	21	38	35.4	33	8
WM155-22	22	38	35.4	33	8
WM155-23	23	38	35.4	35	8
WM155-24	24	38	35.4	35	8
WM155-25	25	40	38.2	35.5	8.5
WM155-28	28	46	43.3	39	9
WM155-29	29	46	43.3	39	9
WM155-30	30	46	43.3	39	9
WM155-32	32	46	43.3	39	9
WM155-33	33	48	53.5	50.5	11.5
WM155-35	35	50	53.5	50.5	11.5
WM155-38	38	58	60.5	50.5	11.5
WM155-40	40	58	60.5	50.5	11.5

WM155B · Metric sizes

Model	d1 (mm)	d3	d7	l1	l3
WM155B-10	10	20	21	15.2	7
WM155B-12	12	22	23	18.2	7
WM155B-14	14	25	25	22.2	7
WM155B-16	16	29	27	23.2	7
WM155B-18	18	33	33	24.2	10
WM155B-20	20	33	35	25.2	10
WM155B-22	22	38	37	25.2	10
WM155B-24	24	38	39	27.2	10
WM155B-25	25	40	40	27.2	10
WM155B-28	28	46	43	29.2	10
WM155B-30	30	46	45	30.2	10
WM155B-32	32	46	48	30.2	10
WM155B-33	33	48	48	39.2	10
WM155B-35	35	50	50	39.2	10
WM155B-38	38	56	56	42.2	13
WM155B-40	40	58	58	42.2	13

Catalog model

WM 156

Pressure: ≤ 0.5 MPa
Speed: ≤ 10 m/s
Temperature: -30 to +200 °C

Rotary ring: Plastic carbon, carbon, SiC, tungsten carbide
Stationary ring: Ceramic, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and metal parts: 304 stainless, 316 stainless

Dimensions on request: send the shaft size, a drawing or the old seal.

Catalog model

WM 166/E

Pressure: ≤ 1 MPa
Speed: ≤ 15 m/s
Temperature: -30 to +200 °C

Rotary ring: Plastic carbon, carbon, SiC, tungsten carbide
Stationary ring: Ceramic, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and metal parts: 304 stainless, 316 stainless

WM166 · Inch sizes

Model	d1 (mm)	d3	d7	l1	l3
WM166-5/16"	7.938	23.29	25.4	24.5	7.9
WM166-3/8"	9.525	23.29	22.225	23.8	7.14
WM166-1/2"	12.7	23.29	25.4	24.8	7.93
WM166-5/8"	15.875	30.1	31.75	28.55	10.31
WM166-3/4"	19.05	33.07	34.925	28.55	10.31
WM166-7/8"	22.225	36.3	38.1	30.94	10.31
WM166-1"	25.4	39.42	41.275	31.72	11.1

WME · Inch sizes

Model	d1 (mm)	d3	d7	l1	l3
WME-3/8"A	9.53	23.8	22.23	16.08	6.35
WME-3/8"	9.53	26.97	25.4	16.86	7.93
WME-1/2"A	12.7	26.97	25.4	16.86	6.35
WME-1/2"	12.7	26.97	25.4	16.86	7.93
WME-5/8"	15.88	30.94	31.75	18.44	10.31
WME-3/4"	19.05	34.11	34.93	18.44	10.31
WME-7/8"	22.23	42.85	41.28	20.82	11.1
WME-1"	25.4	42.85	41.28	20.82	11.1

Catalog model

WM 166T

Pressure: ≤ 0.5 MPa
Speed: ≤ 10 m/s
Temperature: -30 to +200 °C

Rotary ring: Carbon, SiC, tungsten carbide
Stationary ring: Ceramic, SiC, tungsten carbide
Cup gasket: NBR, EPDM, Viton
Spring: 304 stainless, 316 stainless
Drive ring: 304 stainless, 316 stainless
Retainer: 304 stainless, 316 stainless
Bellows: NBR, EPDM, Viton

WM166T · Inch sizes

Model	d1 (mm)	d3	d7	l1	l3
WM166T-3/8"	9.525	23.292	24.587	34.138	8.738
WM166T-7/16"	11.1	22	30	26	5.4
WM166T-1/2"	12.7	23.292	27.788	34.138	8.738
WM166T-5/8"	15.875	30.099	30.937	35.712	10.312
WM166T-3/4"	19.05	33.071	33.1/34.138	35.712	6.5/10.312
WM166T-7/8"	22.225	36.297	37.287	35.712	10.312
WM166T-1"	25.4	39.421	40.488/41.28	43.307	10.3/11.1
WM166T-1 1/8"	28.575	44.45	47.625	44.907	11.913
WM166T-1 1/4"	31.75	47.625	50.8	44.907	11.913
WM166T-1 3/8"	34.925	50.8	53.975	44.907	11.913
WM166T-1 1/2"	38.1	53.975	57.15	44.907	11.913
WM166T-1 5/8"	41.275	60.325	60.325	44.907	11.913
WM166T-1 3/4"	44.45	60.325	63.5	52.934	11.913
WM166T-1 7/8"	47.625	63.881	66.675	52.934	11.913
WM166T-2"	50.8	69	69.85	54.508	13.487
WM166T-3"	76.2	98.4	101.6	68.25	15.875

WM166T · Metric sizes

Model	d1 (mm)	d3	d7	l1	l3
WM166T-12	12	23.3	27.8	34.1	8.7
WM166T-16	16	30.1	30.95	35.7	10.3
WM166T-20	20	36.3	35.7	35.7	10.3
WM166T-22	22	36.3	37.3	35.7	10.3
WM166T-24	24	39.4	40.5	35.7	10.3
WM166T-25	25	39.4	40.5	35.7	10.3
WM166T-28	28	44.4	47.65	45.2	11.9
WM166T-30	30	47.6	50.8	45.2	11.9
WM166T-32	32	47.6	50.8	45.2	11.9
WM166T-35	35	50.8	54	45.2	11.9
WM166T-38	38	54	57.15	45.2	11.9
WM166T-40	40	60.3	60.35	45.2	11.9
WM166T-45	46	66.7	63.5	52.4	11.9
WM166T-48	48	66.7	66.7	52.4	11.9
WM166T-50	50	69	69.85	54	13.5
WM166T-55	55	74.6	73.05	54	13.5

Catalog model

WM 70

Pressure: ≤ 0.6 MPa
Speed: ≤ 10 m/s
Temperature: -30 to +200 °C

Rotary ring: Plastic carbon, carbon, SiC, tungsten carbide
Stationary ring: Ceramic, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and metal parts: 304 stainless, 316 stainless

Model	d1 (mm)	d7	d3	l1	l3
WM70-10	10	25.4	22.6	19	5.6
WM70-13	13	29.5	31.5	32	8
WM70-14	14	29.5	31.5	32	8
WM70-15	15	29.5	31.5	26/32	8
WM70-16	16	29.5	31.5	26/32	8

Catalog model

WM FBD

Pressure: ≤ 1 MPa
Speed: ≤ 12 m/s
Temperature: -30 to +200 °C

Stationary ring: Ceramic, SiC, tungsten carbide
Rotary ring: Carbon, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and pressed parts: Steel

WMFBD · Metric sizes

Model	d1 (mm)	d3	d7	l3	l1
WMFBD-16	16	34	30	8	25.2
WMFBD-18	18	36.8	32	8	25.2
WMFBD-20	20	38.8	34	8	25.2
WMFBD-22	22	41.5	36	8	25.2
WMFBD-25	25	44.8	39	8	26.2
WMFBD-28	28	48.5	43	8	26.2
WMFBD-30	30	52	48	8	26.2
WMFBD-35	35	57	53	10	30.2
WMFBD-40	40	67	58	10	34.2
WMFBD-45	45	73	63	10	36.2
WMFBD-50	50	79	68	10	41.2
WMFBD-55	55	84	73	12	41.2
WMFBD-60	60	90	79	12	41.2
WMFBD-65	65	98.5	86	12	49.2
WMFBD-70	70	103.5	91	12	52.2
WMFBD-75	75	110.5	96	12	52.2
WMFBD-80	80	120	105	14	56.2
WMFBD-85	85	125	110	14	56.2
WMFBD-90	90	132	115	14	56.2
WMFBD-95	95	137	120	14	56.2
WMFBD-100	100	144	125	14	62.2
WMFBD-110	110	157	135	16	62.2
WMFBD-120	120	169.5	145	16	72.2

WMFBD · Inch sizes

Model	d1 (mm)	d3	d7	l3	l1
WMFBD-5/8"	15.87	34	30.95	10.3	25.2
WMFBD-3/4"	19.05	38.8	34.15	10.3	25.2
WMFBD-7/8"	22.22	41.5	37.3	10.3	25.2
WMFBD-1"	25.4	44.8	40.5	10.3	25.2
WMFBD-1 1/8"	28.57	48.5	47.65	11.9	33.2
WMFBD-1 1/4"	31.75	57	50.8	11.9	33.2
WMFBD-1 3/8"	34.92	57	54	11.9	33.2
WMFBD-1 1/2"	38.1	67	57.15	11.9	33.2
WMFBD-1 5/8"	41.27	67	60.35	11.9	33.2
WMFBD-1 3/4"	44.45	73	63.5	11.9	41.2
WMFBD-1 7/8"	47.62	73	66.7	11.9	41.2
WMFBD-2"	50.8	79	69.85	13.5	41.2
WMFBD-2 1/8"	53.97	84	73.05	13.5	41.2
WMFBD-2 1/4"	57.15	84	76.2	13.5	41.2
WMFBD-2 3/8"	60.32	90	79.4	13.5	41.2
WMFBD-2 1/2"	63.5	94	82.55	13.5	41.2

Catalog model

WM 560A/B

Pressure: ≤ 1 MPa
Speed: ≤ 12 m/s
Temperature: -30 to +200 °C

Stationary ring: Ceramic, SiC, tungsten carbide
Rotary ring: Carbon, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and pressed parts: Steel

WM560A · Metric sizes

Model	d1 (mm)	d3	d6	d7	l1	l3
WM560A-10	10	23.5	16	24	25	7
WM560A-11	11	23.5	16	24	25	7
WM560A-12	12	26	17	26	25	7
WM560A-14	14	28	21	28	25.5	7
WM560A-15	15	30	21	28	29.5	7
WM560A-16	16	32	22	32	33.5	10
WM560A-18	18	32.5	25	35	36.5	10
WM560A-19	19	32.5	25	35	36.5	10
WM560A-20	20	35.5	27	38	38	10
WM560A-22	22	37.5	29	40	40.3	10
WM560A-25	25	42	32	44	39.3	10
WM560A-28	28	47	34	46	40	10
WM560A-30S	30	46	35	45	38.2	7.5
WM560A-30L	30	48	38	50	40	10
WM560A-32	32	50	40	54	40	10
WM560A-35	35	54.5	44	58	42	10
WM560A-38	38	58.5	46	60	42.6	10
WM560A-40	40	62.5	48	64	42.6	10
WM560A-45	45	66.5	52	66	45	10
WM560A-50	50	72.5	58	72	54.6	11.5
WM560A-55S	55	72	60	75	59.4	12

WM560B · Inch sizes

Model	d1 (mm)	d3	d6	d7	l1	l3
WM560B-3/8"	9.525	23.5	14.3	22.23	28.6	7.9
WM560B-1/2"	12.7	26	17.5	25.4	28.6	7.9
WM560B-5/8"	15.875	30	20.6	31.75	32.5	10.3
WM560B-3/4"	19.05	32.5	23.8	34.93	32.5	10.3
WM560B-7/8"	22.225	37.5	27	38.1	34.1	10.3
WM560B-1"	25.4	44	30.2	41.28	36.5	11.1
WM560B-1 1/8"	28.575	48	33.3	44.45	38.1	11.1
WM560B-1 1/4"	31.75	50	36.5	47.63	38.1	11.1
WM560B-1 3/8"	34.925	54.5	39.7	50.8	39.7	11.1
WM560B-1 1/2"	38.1	58.5	42.9	53.98	39.7	11.1
WM560B-1 5/8"	41.275	64	46	60.33	47.6	12.7
WM560B-1 3/4"	44.45	67	49.2	63.5	47.6	12.7
WM560B-1 7/8"	47.625	71	52.4	66.68	50.8	12.7
WM560B-2"	50.8	73.5	55.6	69.85	50.8	12.7
WM560B-2 1/8"	53.975	75.6	\	76.2	57.2	14.3
WM560B-2 1/4"	57.15	80	65	79.38	57.2	14.3
WM560B-2 3/8"	60.325	79.6	\	82.55	57.2	14.3
WM560B-2 1/2"	63.5	84.9	70	85.73	60.3	14.3
WM560B-2 5/8"	66.675	84.6	\	85.725	65.1	15.9
WM560B-2 3/4"	69.85	93	\	88.9	65.1	15.9
WM560B-3"	76.2	102	\	98.425	68.3	15.9

Catalog model

WM BIA

Pressure: ≤ 1 MPa
Speed: ≤ 10 m/s
Temperature: -30 to +200 °C

Stationary ring: Ceramic, SiC, tungsten carbide
Rotary ring: Carbon, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and pressed parts: Steel

Model	d (mm)	d3	d7	l1	l2
WMBIA-14	14	27	30	23.7	5
WMBIA-16	16	28.5	32	26	5
WMBIA-18	18	30.5	35	30	7.5
WMBIA-20	20	34	35	29	8
WMBIA-25	25	39	40	33.5	8
WMBIA-28	28	42	43	33.5	8
WMBIA-30	30	44	45	34.5	9
WMBIA-32	32	47	48	42.5	9
WMBIA-33	33	47	48	42.5	9
WMBIA-35	35	49	50	42.5	9
WMBIA-38	38	54	56	42.5	9
WMBIA-40	40	56	58	42.5	9
WMBIA-43	43	59	61	46	9.5
WMBIA-45	45	62	63	47.5	9.5
WMBIA-48	48	64	66	47.5	9.5
WMBIA-50	50	66	70	47.5	9.5
WMBIA-53	53	69	73	50.5	9.5
WMBIA-55	55	72	75	50.5	9.5
WMBIA-58	58	80	78	51.5	9.5
WMBIA-60	60	80	80	51.5	9.5
WMBIA-70	70	90	92	56	11

Catalog model

WM 20

Pressure: ≤ 0.8 MPa
Speed: ≤ 10 m/s
Temperature: -20 to +150 °C

Stationary ring: Ceramic, SiC, tungsten carbide
Rotary ring: Carbon, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and pressed parts: Steel

WM20 · Inch sizes

Model	d1 (mm)	d3	d7	l3	l1
WM20-3/8"	9.5	22.95	24.6	8.74	25.6
WM20-1/2"	12.7	23.9	27.79	8.74	25.6
WM20-5/8"	15.8	26.7	30.95	10.32	25.6
WM20-3/4"	19.1	31.1	34.15	10.32	25.6
WM20-7/8"	22.2	33.4	37.3	10.32	25.6
WM20-1"	25.4	43.2	40.5	10.32	25.6
WM20-1 1/8"	28.6	46.3	47.63	11.99	33.54
WM20-1 1/4"	31.7	49.4	50.8	11.99	33.54
WM20-1 3/8"	34.9	52.6	53.98	11.99	33.54
WM20-1 1/2"	38.1	55.8	57.15	11.99	33.54
WM20-1 5/8"	41.2	62.2	60.35	11.99	33.54
WM20-1 3/4"	44.4	66	63.5	11.99	40.68
WM20-1 7/8"	47.6	66.6	66.7	11.99	40.68
WM20-2"	50.8	73	69.85	11.99	40.68
WM20-2 1/8"	53.9	73.3	73.05	13.5	41.2
WM20-2 1/4"	57.1	78.4	76.2	13.5	41.2
WM20-2 3/8"	60.3	82	79.4	13.5	41.2
WM20-2 1/2"	63.5	84.9	82.55	13.5	41.2
WM20-2 5/8"	66.6	88.4	92.1	15.9	49.2
WM20-2 3/4"	69.8	92.6	95.25	15.9	49.2
WM20-2 7/8"	73	94.85	98.45	15.9	49.2
WM20-3"	76.2	101.9	101.65	15.9	49.2

WM20 · Metric sizes

Model	d1 (mm)	d3	d7	l3	l1
WM20-10	10	22.95	24.6	8.74	25.6
WM20-12	12	23.9	27.79	8.74	25.6
WM20-13	13	23.9	27.79	8.74	25.6
WM20-14	14	26.7	30.95	10.32	25.6
WM20-15	15	26.7	30.95	10.32	25.6
WM20-16	16	26.7	30.95	10.32	25.6
WM20-18	18	31.1	34.15	10.32	25.6
WM20-19	19	31.1	34.15	10.32	25.6
WM20-20	20	33.4	35.7	10.32	25.6
WM20-22	22	33.4	37.3	10.32	25.6
WM20-24	24	39.2	40.5	10.32	25.6
WM20-25	25	39.2	40.5	10.32	25.6
WM20-28	28	46.3	47.63	11.99	33.54
WM20-30	30	49.4	50.8	11.99	33.54
WM20-32	32	49.4	50.8	11.99	33.54
WM20-33	33	52.6	53.98	11.99	33.54
WM20-34	34	52.6	53.98	11.99	33.54
WM20-35	35	52.6	53.98	11.99	33.54
WM20-38	38	55.8	57.15	11.99	33.54
WM20-40	40	62.2	60.35	11.99	33.54
WM20-42	42	66	63.5	11.99	40.68
WM20-43	43	66	63.5	11.99	40.68
WM20-44	44	66	63.5	11.99	40.68
WM20-45	45	66	63.5	11.99	40.68
WM20-48	48	66.6	66.7	11.99	40.68
WM20-50	50	71.65	69.85	11.99	40.68
WM20-53	53	73.3	73.05	13.5	41.2
WM20-55	55	78.4	76.2	13.5	41.2
WM20-58	58	82	79.4	13.5	41.2
WM20-60	60	82	79.4	13.5	41.2
WM20-63	63	84.9	82.55	13.5	41.2
WM20-65	65	88.4	92.1	15.9	49.2
WM20-70	70	92.6	95.52	15.9	49.2
WM20-73	73	94.85	98.45	15.9	49.2
WM20-75	75	101.9	101.65	15.9	49.2

Catalog model

WM 24

Pressure: ≤ 0.8 MPa
Speed: ≤ 10 m/s
Temperature: -20 to +150 °C

Stationary ring: Ceramic, SiC, tungsten carbide
Rotary ring: Carbon, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and pressed parts: Steel

Model	d1 (mm)	d3	d7	l3	l1
WM24-12	12	21.7	23	8.6	24.1
WM24-14	14	24.5	25	8.6	26.6
WM24-16	16	26.65	27	8.6	26.6
WM24-18	18	30.35	33	10	27.7
WM24-20	20	33.4	35	10	27.7
WM24-22	22	33.55	37	10	27.7
WM24-24	24	38.3	39	10	30.2
WM24-25	25	39.3	40	10	30.2
WM24-28	28	42.2	43	10	32.7
WM24-30	30	43.95	45	10	32.7
WM24-32	32	45.75	48	10	32.7
WM24-33	33	45.85	48	10	32.7
WM24-35	35	49.1	50	10	32.7
WM24-38	38	52.6	56	11	34.2
WM24-40	40	55.7	58	11	34.2
WM24-43	43	58.8	61	11	34.2
WM24-45	45	61	63	11	34.2
WM24-48	48	64.2	66	11	34.2
WM24-50	50	66.6	70	13	34.7
WM24-55	55	71.65	75	13	34.7
WM24-58	58	78.4	78	13	39.7
WM24-60	60	78.4	80	13	39.7
WM24-63	63	81.5	83	13	39.7
WM24-65	65	84.3	85	13	39.7
WM24-68	68	89.65	90	15.3	37.4
WM24-70	70	89.65	92	15.3	44.9
WM24-75	75	96.8	97	15.3	44.9

Catalog model

WM 301

Pressure: ≤ 0.6 MPa
Speed: ≤ 10 m/s
Temperature: -30 to +200 °C

Stationary ring: Ceramic, SiC, tungsten carbide
Rotary ring: Carbon, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and pressed parts: Steel

Model	d1 (mm)	d3	d6	d7	l1	l3
WM301-6	6	18	8	22	14	4
WM301-8S	8	18	10	22	15	4
WM301-8M	8	20	10	22/26	15/16.5	4.0/5.5
WM301-8L	8	24	10	26	16.5	5.5
WM301-10	10	24	12	26	21	8
WM301-11	11	24	13	26	21	8
WM301-12	12	24	14	25/26	21	8
WM301-13	13	24	15	26	18.5/21	5.5/8.0
WM301-13L	13	28	16	28	21	8
WM301-13H	13	32	16	29.5	30.5	8
WM301-14	14	28	16	28/28.5	21	8
WM301-14L	14	32	16	29.5	21	8
WM301-15S	15	28	16	28.5/30	21	8
WM301-15M	15	32	16	30/29.5	21	8
WM301-15L	15	39	18	38	21	8
WM301-16S	16	28	16	29.5/30	21	8
WM301-16M	16	32	18	29.5	21	8
WM301-16L	16	39	18	38	21	8
WM301-16H	16	32	16	30	29	10
WM301-17	17	39	19	42	21	8
WM301-18	18	39	20	42	21	8
WM301-19	19	39	21	42	21	8
WM301-20	20	39	22	42	21	8
WM301-20L	20	42	24	45	23	10
WM301-22S	22	36	24	45	26.5	10
WM301-22L	22	42	24	45	23	10
WM301-23	23	47	25	50	23.5	10
WM301-24	24	47	26	50	23.5	10
WM301-25	25	42	27	50	23.5	10
WM301-25L	25	47	27	50	23.5	10
WM301-26	26	47	29	50	23.5	10
WM301-27	27	47	30	50	23.5	10
WM301-28	28	54	31	57	25	10
WM301-30	30	54	33	57	25	10
WM301-32	32	54	35	57	25	10
WM301-35	35	60	38	63	26	10
WM301-38	38	65	41	68	30	12
WM301-40	40	65	43	68	30	12
WM301-45	45	70	48	73	32	12
WM301-50	50	85	52	88	38	15
WM301-55	55	85	58	88	38	15
WM301-60	60	105	63	110	45	15
WM301-65	65	105	\	110	47	15
WM301-70	70	105	\	110	47	15

Catalog model

WM 960

Pressure: ≤ 1.2 MPa
Speed: ≤ 15 m/s
Temperature: -30 to +200 °C

Stationary ring: Ceramic, SiC, tungsten carbide
Rotary ring: Carbon, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and pressed parts: Steel

Model	d1 (mm)	d3	d7	l1	l3
WM960-14	14	24.5	25	35	8
WM960-16	16	26.8	27	35	8
WM960-18	18	31.8	33	37.5	10
WM960-20	20	32.5	35	37.5	10
WM960-22	22	36.5	37	37.5	10
WM960-24	24	38.8	39	40	10
WM960-25	25	38.8	40	40	10
WM960-28	28	46.5	43	42.5	10
WM960-30	30	46.5	45	42.5	10
WM960-32	32	46.5	48	42.5	10
WM960-33	33	49.5	48	42.5	10
WM960-35	35	49.5	50	42.5	11
WM960-38	38	54	56	45	11
WM960-40	40	57	58	45	11
WM960-43	43	61.5	61	45	11
WM960-45	45	61.5	63	45	11
WM960-48	48	70.6	66	45	11
WM960-50	50	70.6	70	47.5	11
WM960-53	53	70.6	73	47.5	12
WM960-55	55	76	75	47.5	12
WM960-58	58	79.6	78	52.5	12
WM960-60	60	79.6	80	52.5	12
WM960-63	63	84.6	83	52.5	12
WM960-65	65	84.6	85	52.5	13

Catalog model

WM 502

Usually corresponds to the John Crane Type 502 style.

WM 502 section drawing with dimension letters

Pressure: ≤ 1.2 MPa
Speed: ≤ 12 m/s
Temperature: -30 to +200 °C

Rotary ring: Carbon, SiC, tungsten carbide
Stationary ring: Ceramic, SiC, tungsten carbide
Secondary seals: NBR, EPDM, Viton
Spring and metal parts: 304 stainless, 316 stainless

Model	d1 (mm)	d3	d7	l3	l1
WM502-14	14	24	25	12	23.2
WM502-16	16	26	27	12	23.2
WM502-18	18	32	33	13.5	24.2
WM502-20	20	34	35	13.5	24.2
WM502-22	22	36	37	13.5	24.2
WM502-24	24	38	39	13.3	26.9
WM502-25	25	39	40	13	27.2
WM502-28	28	42	43	12.5	30.2
WM502-30	30	44	45	11.9	30.7
WM502-32	32	46	48	11.9	30.7
WM502-33	33	47	48	11.9	30.7
WM502-35	35	49	50	11.9	30.7
WM502-38	38	54	56	12.9	32.2
WM502-40	40	56	58	12.9	32.2
WM502-43	43	59	61	12.9	32.2
WM502-45	45	61	63	12.9	32.2
WM502-48	48	64	66	12.9	32.2
WM502-50	50	66	70	13.4	34.2
WM502-53	53	69	73	13.4	34.2
WM502-55	55	71	75	13.4	34.2
WM502-58	58	78	78	13.4	39.2
WM502-60	60	80	80	13.4	39.2
WM502-63	63	83	83	13.4	39.2
WM502-65	65	85	85	13.4	39.2
WM502-68	68	88	90	13.4	39.2
WM502-70	70	89	92	14.5	45.7
WM502-75	75	96	97	14.5	45.7
WM502-80	80	104	105	15	45.2
WM502-85	85	109	110	15	45.2
WM502-90	90	114	115	15	50.2
WM502-95	95	119	120	15	50.2
WM502-100	100	124	125	15	50.2

FAQ

Rubber Bellows Seal FAQ

My seal is not in the table. Can you still make it?

Yes. The catalog shows our standard sizes; we build most other rubber bellows seals from a drawing, a part number or the old seal. To quote, send the seal part number, a drawing or the old seal.

Which face pair should I choose?

Carbon against ceramic suits clean water; carbon or SiC against SiC suits hotter or dirtier duty; SiC or tungsten carbide pairs suit abrasive fluids. Tell us the fluid, temperature and pressure and we confirm the pair.

Rubber bellows or metal bellows?

A rubber bellows is the economical choice for water and utility duty within the elastomer’s temperature range. For high temperature or fluids that attack elastomers, see our metal bellows seals.

Source Rubber Bellows Seals At Scale

Catalog sizes, custom sizes and private-label rubber bellows seals built in-house at low minimums. Send the seal drawing, the seal model or a sample and we’ll quote.

Request a quote →All seal types