DIAPHRAGM SEALS

H21

  • Diaphragm w/ Drive Band
  • To Imperial Dimensions
  • General purpose
  • Bi-directional

H21 is a mechanical seal for imperial shafts, based on the industry standard "Type 21" design. It is widely used for its low cost / high efficiency ratio.

 

A rubber diaphragm is secured to the shaft with a drive band, which seres as both a secondary seal and positive torque element.

 

Mechanical compression on the spring-cap is typically delivered by a shoulder in the shaft / sleeve, threaded impeller or setting collar (available separately).

PARTS

A

B

C

D

E

F

G

H

Stationary Cup

Stationary Face / Ring

Rotary Face / Ring

Rotary Retainer

Rotary Diaphragm

Rotary Drive Band

Spring

Spring Cap

SEAT OPTIONS

CM

OG

N (G50)

W

standard

o-ring

Euro cup

Euro o-ring

EQUIVALENT

  • Operating conditions¹

Temperature:

Pressure:

Speed:

-30°C to +200°C

< 10 bar, 145 psi, 1 MPa

< 13m/s, 2500 fpm

rpm < 780000/(79.8 x D1)

¹Guide-values only (due to diversity of possible applications). Enquire for specific-use cases. Maximum values of each parameter cannot be applied together.

T21

P04

Type 11

Type 31

MG912/d1-G55

21A

RB821

DATA SHEET

  • Material options

Rotary Face:

Stationary Face:

Elastomer:

Metal Parts:

CAB, SiC or TC

CER, SiC or TC

N, V or EP

304S.S.

H21 - Data Sheet

TYPE 21

PRODUCT INFORMATION

DIMENSIONS

Dimensions refer to installed length, not 'free' length: