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MD251

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Item	Description
1, 11	Seal face
2, 8, 10, 12, 16, 19	O-Ring
3	Spacer
4	Thrust ring
5	Collar
6, 13	Spring
7, 14, 21, 22, 24	Pin
9, 15	Seat
17	Gasket
18	Seal cover
20	Shaft sleeve
23	Drive collar
25	Set screw
26	Assembly fixture
27	HSH cap screw

MD251

PDF data sheet

Features

Cartridge design
Balanced
Double seal
Independent of direction of rotation
Springs do not contact the liquid
Inboard seal can withstand both forward and back pressure

Advantages

Equipped with flushing, quenching, and drainports as standard
PTFE backup ring as standard

Operating range

Pressure: p = vacuum … 16 bar (232 PSI)
Temperature:
t = -20 °C … 160 °C (-4 °F … 320 °F) (oil),
0 °C … 80 °C (32 °F … 176 °F) (water)
Sliding velocity: vg = 20 m/s (66 ft/s)
Viscosity: … 1 Pa·s
Solids content: … 7 %

Materials

Seal face (inboard side): Silicon carbide (Q1)
Seal face (atmosphere side): High density carbon graphite
Seat: Silicon carbide (Q1)
Metal parts: CrNiMo steel (G)
Secondary seals: FKM (V)

Recommended applications

Acids
Alkaline solutions
Salt solutions
Low viscosity oils
Monomers
Hydrocarbons
Water
Seawater
Petrochemical industry
Chemical industry
Pharmaceutical industry
Pulp and paper industry
Water and waste water technology
Food and beverage industry
Metal production and processing
Chemical pumps
Process pumps

Similar products

Cartex
Dual seals

Dual seal
Cartridge
Balanced
Independent of direction of rotation
Double pressure balanced
Integrated pumping device
Variants available: for eccentric screw pumps (-Vario) and gas-lubricated version (-GSDN)

Cartex
Single seals

Single seal
Cartridge
Balanced
Independent of direction of rotation
Single seals without connections (-SNO), with flush (-SN) and with quench combined with lip seal (-QN) or throttle ring (-TN)
Additional variants available for ANSI pumps (e.g. -ABPN) and eccentric screw pumps (-Vario)

Cartex ANSI
Dual seals

Dual seal
Available for standard (Cartex-ASDN) and big bore (Cartex-ABDN) seal chambers
Cartridge
Balanced
Independent of direction of rotation
Double pressure balanced
Integrated pumping device

Back to overview

d	d_s1	d~2 min.~	d~2 max.~	d₃	d₄	d₅	l₁	l₂	l₃	l₄	l₅	l₆
20	34	36	51	38	58	104	49	42	23	60	12	18
25	39	41	51	43	58	104	49	42	23	60	12	18
30	44	46	56	48	63	108	49	42	23	65	12	18
35	49	51	66	53	73	118	49	42	23	75	14	16
40	56	58	66	60	73	118	49	42	23	75	14	16
45	61	63	71	65	78	128	49	42	23	80	14	16
50	68	70	81	72	88	138	51	42	23	90	14	16
55	73	75	81	77	88	138	51	42	23	90	14	16
60	78	80	96	82	103	164	54	45	23	105	18	14
65	84	86	96	88	103	164	54	45	23	105	18	14
70	90	92	102	94	109	178	54	45	23	111	18	14
75	99	102	114	104	121	193	57	45	23	123	18	14
80	104	107	114	109	121	193	57	45	23	123	18	14
85	109	112	124	114	131	208	57	45	23	133	20	13
90	114	117	124	119	131	208	57	45	23	133	20	13
95	119	122	134	124	141	218	57	45	23	143	20	13
100	124	127	134	129	141	218	57	45	23	143	20	13

Dimensions in Millimeter

d	d_s1	d~2 min.~	d~2 max.~	d₃	d₄	d₅	l₁	l₂	l₃	l₄	l₅	l₆
20	34	36	51	38	58	104	49	42	23	60	12	18
25	39	41	51	43	58	104	49	42	23	60	12	18
30	44	46	56	48	63	108	49	42	23	65	12	18
35	49	51	66	53	73	118	49	42	23	75	14	16
40	56	58	66	60	73	118	49	42	23	75	14	16
45	61	63	71	65	78	128	49	42	23	80	14	16
50	68	70	81	72	88	138	51	42	23	90	14	16
55	73	75	81	77	88	138	51	42	23	90	14	16
60	78	80	96	82	103	164	54	45	23	105	18	14
65	84	86	96	88	103	164	54	45	23	105	18	14
70	90	92	102	94	109	178	54	45	23	111	18	14
75	99	102	114	104	121	193	57	45	23	123	18	14
80	104	107	114	109	121	193	57	45	23	123	18	14
85	109	112	124	114	131	208	57	45	23	133	20	13
90	114	117	124	119	131	208	57	45	23	133	20	13
95	119	122	134	124	141	218	57	45	23	143	20	13
100	124	127	134	129	141	218	57	45	23	143	20	13

d	d_s1	d~2 min.~	d~2 max.~	d₃	d₄	d₅	l₁	l₂	l₃	l₄	l₅	l₆
20	34	36	51	38	58	104	49	42	23	60	12	18
25	39	41	51	43	58	104	49	42	23	60	12	18
30	44	46	56	48	63	108	49	42	23	65	12	18
35	49	51	66	53	73	118	49	42	23	75	14	16
40	56	58	66	60	73	118	49	42	23	75	14	16
45	61	63	71	65	78	128	49	42	23	80	14	16
50	68	70	81	72	88	138	51	42	23	90	14	16
55	73	75	81	77	88	138	51	42	23	90	14	16
60	78	80	96	82	103	164	54	45	23	105	18	14
65	84	86	96	88	103	164	54	45	23	105	18	14
70	90	92	102	94	109	178	54	45	23	111	18	14
75	99	102	114	104	121	193	57	45	23	123	18	14
80	104	107	114	109	121	193	57	45	23	123	18	14
85	109	112	124	114	131	208	57	45	23	133	20	13
90	114	117	124	119	131	208	57	45	23	133	20	13
95	119	122	134	124	141	218	57	45	23	143	20	13
100	124	127	134	129	141	218	57	45	23	143	20	13

MD251

MD251

Features

Advantages

Operating range

Materials

Recommended applications

Similar products

CartexDual seals

CartexSingle seals

Cartex ANSIDual seals

Cartex
Dual seals

Cartex
Single seals

Cartex ANSI
Dual seals

d	d_s1	d~2 min.~	d~2 max.~	d₃	d₄	d₅	l₁	l₂	l₃	l₄	l₅	l₆
20	34	36	51	38	58	104	49	42	23	60	12	18
25	39	41	51	43	58	104	49	42	23	60	12	18
30	44	46	56	48	63	108	49	42	23	65	12	18
35	49	51	66	53	73	118	49	42	23	75	14	16
40	56	58	66	60	73	118	49	42	23	75	14	16
45	61	63	71	65	78	128	49	42	23	80	14	16
50	68	70	81	72	88	138	51	42	23	90	14	16
55	73	75	81	77	88	138	51	42	23	90	14	16
60	78	80	96	82	103	164	54	45	23	105	18	14
65	84	86	96	88	103	164	54	45	23	105	18	14
70	90	92	102	94	109	178	54	45	23	111	18	14
75	99	102	114	104	121	193	57	45	23	123	18	14
80	104	107	114	109	121	193	57	45	23	123	18	14
85	109	112	124	114	131	208	57	45	23	133	20	13
90	114	117	124	119	131	208	57	45	23	133	20	13
95	119	122	134	124	141	218	57	45	23	143	20	13
100	124	127	134	129	141	218	57	45	23	143	20	13