A Double Seal and How it Works

A double seal aka dual seal is a mechanical seal that’s designed to ensure the highest sealing safety. Double seals are used to mitigate the leakage of fluids and gases in pumps and mixers.

Why Double Seals?

Double seals are preferred over single seals as they provide greater safety and ensure that there are no unnecessary emissions during the pumping and mixing of toxic substances. Companies use double seals to meet their environmental goals and emission requirements. Double seals allow them to acquire greater control over the seal operating environment.

How Does a Double Seal Work?

A double seal generally consists of two serially arranged seals. The primary seal is generally referred to as inboard and it ensures that the product doesn’t leak from the pump housing.

The secondary seal or the outboard keeps the flush liquid from leaking into the environment.

Types of Double Seals

The dual mechanical seals generally come in two types of arrangements. Let’s have a look;

Back to Back

In this type of arrangement, both the primary and the secondary seals are arranged back to back in a way that they face opposite to each other. The barrier fluid forms a lubricating film and penetrates the product if there’s a leakage. Back-to-back double seals are generally found in chemical industries and workplaces.

Face to Face

In the face-to-face seal arrangement, the primary seal is mounted inside the stuffing box and the secondary seal is adjusted outside. This arrangement can be easily installed and can be tested by using air as the barrier fluid.

Typically, face-to-face mechanical seals are used in the food manufacturing industries. When there is a leakage the barrier fluid penetrates the product and if the product gets hot the barrier serves as a cooling agent and maintains the environment.

Common Uses of Double Mechanical Seals

The dual mechanical seals are typically employed under the following circumstances;

  • If the fluids are toxic to the external environment and need to be adequately contained.
  • If the polymerizing media is used under extreme temperatures and pressures.

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We offer high-quality engineered sealing solutions to our clients at affordable rates. Whether you’re looking for industrial mixer seal repair, mechanical seal repair in Texas, or searching for a manufacturing company that can custom-design mechanical seals according to your specifications, feel free to contact us.

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