Type SEW Single Mechanical Seals for Sulzer Process Pumps

Equivalent with John Crane Safematic Seal, Sh-Sc-Sew          

Type SEW is a seal operating on a non-pressurized water quench principle.

 It is designed for the most demanding applications in the pulp industry, where reliable

 and long-lasting operation is required from a seal. Typical applications include stock

 pumps at pulp mill washing and screening facilities, as well as high-temperature

 condensate pumps.

Features

Balanced design — undisturbed operation even with sudden pressure shocks.

Heat shrunk seal faces — ensures correct face alignment at all temperatures recommended 

for this seal.

Spring located in a stationary body — shaft misalignment does not pump up the spring or 

wear out the O-ring.

Installation against the shaft shoulder — easy installation reduces risk of human error. 

No measurements required for installation.

No drive pins at seals — seal face does not cracks at start-up.

Available in different materials — selection covers all possible single-seal applications.

Non-pressurized seal water quench — possible to cool seal with non-pressurized seal water 

at high temperatures. A V-ring prevents water leakage from the seal.

By using a Sulzer Scanpump cartridge tool, the seal becomes a true cartridge seal.

Available with grease lubrication — the Safeseal Type SEW can be used with grease quench 

to save seal water.

Parameters

TEMPERATURE LIMITS

300°F/150°C

PRESSURE LIMITS

Process pressure: 215 psi(g)/15 bar(g)

SPEED LIMITS

65fps/20m/s

STANDARD MATERIALS

Seal faces: SiC/Carbon or SiC/SiC

O-rings: PTFE, EPDM, Viton

Metals: AISI 329 (standard), titanium, UHB

Springs: Nimonic steel

V-ring: Nitrile

Recommended Applications