What is single seal?

A single mechanical seal consists of stationary and rotating seal faces that are made from one hard and one softer material. A single mechanical seal offers considerable cost and energy savings when used instead of gland packing.

What is a dual seal?

Double (or dual) mechanical seals are designed to ensure maximum sealing safety. These seals virtually eliminate leakage of the fluid or gas being handled in pumps or mixers. Double seals provide a level of safety/zero emissions compliance not possible with single seals.

What is the difference between a single seal and double seal?

Summarizing the Differences

A single seal has two faces, while a double seal has four. A double seal divides faces into rotating and stationary. Single seals use the pump's fluid as a lubricant, while double seals have a dedicated buffer or barrier liquid.

What is a single seal pump?

WHAT IS A SINGLE MECHANICAL SEAL? A single mechanical seal consists of two very flat surfaces that are pressed together by a spring and slide against each other. Between these two surfaces is a fluid film generated by the pumped product. This fluid film prevents the mechanical seal from touching the stationary ring.

What is single acting mechanical seal?

Single-acting mechanical seals are designed with two seal rings with one interface and without any seal liquid chamber. This type of mechanical seal therefore has to be operated either under dry conditions or must be lubricated and cooled by the liquid product.

single Mechanical seal calculation for centrifugal pump

What is a double seal pump?

A double seal, or back-to-back seal, describes two shaft seals mounted back-to-back to provide a higher level of safety and reliability.

What are the types of mechanical seals?

The most common seal types include the following: Balanced seals. Unbalanced seals. Pusher seals.

What is packing seal?

Packing seals have been the most widely used sealing solution for many years. Packing seals use rope-like materials that wrap around the shaft of a pump, filling in dead space and minimizing fluid loss.

What is mechanical sealing?

Mechanical seals are leakage control devices, which are found on rotating equipment such as pumps and mixers to prevent the leakage of liquids and gases from escaping into the environment.

What is gland packing?

The gland packing is a contact-type sealing element. Compared with other types of shaft seals, they are adjustable and suitable for use with pressures and circumferential speeds higher than those radial shaft seal rings are used for (see also Shaft seal).

What is slurry seal?

Slurry seal is a thin asphalt overlay / seal coat that will fill in small cracks and surface imperfections to give the roadway a uniform color and texture. Most importantly it seals the pavement, thus preventing the infiltration of water, which is the most frequent cause of pavement failure.

What is a lip seal?

Lip seals serve to protect lubricated moving parts and they do this by keeping the lubricant inside the bearing, and keeping contamination from dirt or other liquids out. The term lip seal is generally used to refer to what is correctly known as rotary shaft seals or oil seals or radial shaft seals.

What is a labyrinth seal used for?

Labyrinth seals are used for many low-pressure air compressors, especially when robustness is more important than low leakage. They are normally made of metal, mainly aluminum, but thermoplastics can be used for higher corrosion resistance or better rubbing behavior.

What is balanced seal?

A balanced seal is a mechanical seal configuration in which the fluid closing forces on the seal faces have been modified through seal design. Seal balance, or balance ratio of a mechanical seal, is simply the ratio of two geometric areas. These areas are called the closing area (Ac) and the opening area (Ao).

Why seals are used?

Seals are used to prevent the leakage of fluids in rotating equipment. A seal prevents lubricants, such as oil and grease, from entering the environment and (dirty) water from entering the installation.

What is a static seal?

Static seals are categorized as seals whose mating gland parts do not move relative to one another. There is no motion in the sealing surface between the seal and gland.

What is gland in pump?

The gland nut allows the packing material to be compressed to form a watertight seal and prevent water leaking up the shaft when the tap is turned on. The gland at the rotating shaft of a centrifugal pump may be packed in a similar way and graphite grease used to accommodate continuous operation.

How do seals work?

A mechanical seal works by having two very flat (generally within 2-3 light bands flat) lapped flat faces. This allows a shaft to turn while maintaining a seal. It is very difficult for leakage to occur (beyond a vapor) if installed properly and in good condition.

What is a valve gland?

Gland or gland bushing The part of the valve which retains or compresses the stem packing in a stuffing box.

How many types of sealing are there?

There are seven types of sealants that are the most common in construction.

Why seal is used in pump?

Shaft seals prevent liquid escaping from a rotating or reciprocating shaft. This is important for all pumps and in the case of centrifugal pumps several sealing options will be available: packings, lip seals, and all types of mechanical seals – single, double and tandem including cartridge seals.

What are the two main parts of a mechanical seal?

A stationary ring (usually the stationary seat) arranged in the stationary part (casing) Secondary seal (usually O-ring) between these parts.

What is buffer fluid and barrier fluid?

When this fluid is unpressurized, it forms a buffer between the pumped fluid and atmosphere and is commonly referred to as a buffer fluid. When pressurized, it forms a barrier between the pumped fluid and atmosphere and is known as a barrier fluid.

What is API plan 11?

API Plan 11 recirculates flow from a high‐pressure section of the pump, typically the discharge piping, through a flow control orifice to the seal. Plan 11 is the default flush plan for most pumps. API Plan 11.

What is dry mechanical seal?

Dry gas seals are non-contacting, dry-running mechanical face seals that consist of a mating (rotating) ring and a primary (stationary) ring. When operating, lifting geometry in the rotating ring generates a fluid-dynamic lifting force causing the stationary ring to separate and create a gap between the two rings.