What is the difference between inside-mounted and outside-mounted mechanical seals?

- Jun 08, 2018-

Two categories of single mechanical seals are (1) inside-mounted and (2) outside-mounted. The primary difference between the two styles is that inside mounted seals are contained within the equipment seal chamber and outside-mounted seals are mounted external of the equipment housing. See Images 2 and 3 for diagrams of an inside-mounted and outside-mounted single seal.


Inside-mounted mechanical seals :

inside mounted mechanical seal.png

Image 2. Inside mounted seal

inside-mounted mechanical seal.jpg



1. are available in a wide variety of materials and designs

2. have centrifugal forces that tend to reduce leakage

3. usually avoid catastrophic leakage during seal failure


One disadvantage of inside-mounted seals is that they can be more difficult to install and maintenance usually requires disassembling the equipment.


Outside-mounted mechanical seals:


outside mounted seal.png

Image 3. Outside mounted seal

outside-mounted mechanical seal.JPG

outside-mounted mechanical seal.jpg


Outside-mounted seals are:

1. typically easier to install

2. adjustable without complete equipment disassembly

3. accessible—can often be backed-off for cleaning

4. usually less expensive


One disadvantage of outside-mounted seals is that they usually have lower temperature and speed limits due to lack of sufficient heat removal from the seal faces.



Contact Us:

Shaanxi DaoLin Mechanical & Electrical Co.,Ltd

Room1107, Building B, Sail Times Plaza, Hou Wei Zhai, Wei Yang 

District, 710085, Xi’an  City, Shaanxi Province, China

Tel.:+86(029)84523807-802 Fax: +86(029)84523807-808

Email: sales@inseals.com

www.inseals.com