Unbalance Seals

Metal Bellow Unbalanced Mechanical Seal

All-metal welded bellow construction handles high temperatures well beyond PTFE or elastomer-based limits
Unbalanced face design provides a simpler, more economical build for standard-pressure high-temperature service
Spring-less operation eliminates fretting and coil hang-up common in conventional spring assemblies
No dynamic elastomer on the process side, suited to thermal cycling without sealing degradation
Precision-formed convolutions hold consistent closing force through repeated heating and cooling
Resistant to coking and carbon buildup in hydrocarbon-based high-temperature fluids
Reliable in vacuum or near-vacuum conditions where spring-loaded designs can lose consistent face contact

PRODUCT DESCRIPTION

Reliable Sealing for High-Temperature, Moderate-Pressure Service

Installing a metal bellow unbalanced seal involves sliding the welded bellow assembly onto the shaft and locking it at the specified compression length, since the bellow's own metal convolutions generate the closing force in place of a coil spring. The stationary seat is aligned and secured in the gland before final checks, and because there's no dynamic elastomer involved, temperature swings don't introduce the sealing risks common to conventional designs. As an unbalanced construction, it's the more cost-effective route into metal bellow technology — well suited to hot oil lines, thermal fluid systems, and high-temperature process pumps that don't demand the higher pressure handling of a balanced bellow seal. It also holds up reliably in vacuum service, where maintaining face contact without a spring can otherwise be difficult. For complete step-by-step installation instructions and torque specifications, refer to our detailed installation guide on the blog.

TECHNICAL SPECIFICATIONS