Why We Lead with Metal Bellows

Our founder, Hank Slauson, started Flexaseal with one primary mission: to improve customer service in the Welded Metal Bellows mechanical seal market.

Four decades later, a lot has changed.

Over the years, our commitment to solving complex sealing problems has spurred technical advances, innovation, and the expansion of our core product line of welded metal bellows. Now, our product line has grown to encompass various seal styles and solutions, including the world’s first fully split cartridge mechanical seal.

While we manufacture hundreds of mechanical seal models to serve every major market and with technologies beyond metal bellows, our commitment to Hank’s original goal has only strengthened.

From weld integrity to application versatility, here are four reasons we lead with metal bellows.

1. Weld Integrity

We manufacture all of our edge welded metal bellows sealing products from raw materials to completed units in-house at our headquarters manufacturing facility in Williston, Vermont. Each bellows unit starts as a roll of raw sheet stock that undergoes over ten individual processes to become a finished product. The most important step is our precision welding cells. In this process, stamped sheet stock is microscopically welded to form a bellows convolution. This weld is mission-critical to our customer’s success, and our dedication to weld integrity is absolute.

2. Superior Bellows Design

Edge welded metal bellows are problem solvers. We also like to call them problem avoiders. Bellows seals are inherently balanced designs that limit seal face loads for superior mechanical seal life.

They also eliminate the need for a dynamic elastomer, the critical component in all other seal designs. Many users focus on the seal faces, but secondary sealing with o-rings and other elastomers is equally important to the reliability of a mechanical seal. Dynamic elastomers are particularly susceptible to heat, cold, and particulates in the process fluids because they must flex and slide against metal surfaces within the seal. The sealed flexing element in a welded metal bellows is a high alloy such as Hastelloy C-276 or Inconel 718. These alloys are exceptionally corrosion, erosion, and fracture resistant.

3. Self-Cleaning Capabilities

Our rotating welded metal bellows product, the Style RB, is excellent in dirty applications where springs on traditional designs tend to get clogged with debris. The rotating welded metal bellows design uses centrifugal force to expel particulates away from the bellows unit to keep it clean. This is virtually impossible to accomplish reliably in a mechanical seal with springs.

4. Application Versatility

Since there is no dynamic elastomer in a welded metal bellows seal, we can use non-elastomers for the static sealing elements in the harshest applications where molded rubbers cannot perform.

Examples include high-temperature applications like crude vacuum bottoms in refineries at over 700 F and cryogenic services such as liquid nitrogen, where process temperatures can dip below -300 F. Flexaseal solves these problems with our extreme welded metal bellows products (Style 53, 63, 66, Cryo) and secondary static sealing utilizing grafoil packing.

We are also pushing the boundaries of welded metal bellows pressure limitations with our Style HPCS. This product is designed specifically for very high process pressures where the fluid is dirty. An example is a modern crude oil pipeline where seal chamber pressures might exceed 1,000 PSIG. The HPCS is rated up to 1,500 PSIG. We accomplish this high-performance rating with a triple-ply bellows core. This means each bellows leaf is three individual pieces that have been microscopically welded together. The HPCS is the only super-high pressure welded metal bellows design available in the markets we serve.

Supplying Reliable and Versatile Edge-Welded Bellows: A Long-Term Commitment

Our commitment to welded metal bellows is steadfast, and our dedication to engineering and manufacturing performance-proven metal bellows will ensure your equipment runs longer and your operations run smoother.

Flexaseal is leading the welded metal bellows mechanical seal market, and we look forward to deploying this and other technology to solve your sealing problems.

Edge Welded Metal Bellows Introductory Guide