Seal Refurbishment Services

Elastomer Chemical Compatibility

Seal Face Chemical Compatibility

DIAPHRAGM SEALS

H21

  • Diaphragm / band drive
  • General purpose
  • Industry standard

H21 is the most widely used mechanical seal due to its low cost / high efficiency ratio. It is a diaphragm, parallel spring mechanical seal which is self-aligning and positively driven via a drive band.

 

It is designed to suit imperial shaft sizes and widely configurable to suit both US and Euro installation requirements. For straight shafts, a setting collar can be supplied.

  • Operating conditions

PARTS

A

B

C

D

E

F

G

H

Seat Cup

Seat (CM Standard)

Rotary Face

Retainer

Rubber Diaphragm

Drive Band

Spring

Spring Cap

EQUIVALENT

Type 21

P04

P04U

Type 11

MG9

Temperature:

Pressure:

Speed:

-30°C to 200°C

up to 10 bar, 145 psi

up to 13m/s, 2500 fpm

STANDARD SEAT

  • Material options

CM, G55

OG

US imperial cup seat

US imperial o-ring seat

Rotary Face:

Stationary Face:

Elastomer:

Metal Parts

CAB, SiC, TC

CER, SiC, TC

N, V or EP

Stainless Steel

ALTERNATIVE SEAT

N, G50

W

Euro imperial cup seat

Euro imperial o-ring seat

DATA SHEET

H21 - Data Sheet

TYPE 21

PRODUCT INFORMATION

DIMENSIONS

note: dimensions refer to installed length, not 'free' length