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

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 single mechanical seal?

A single mechanical seal is a type of mechanical seal which consists of one primary seal and it seals from process to atmosphere. There is always some leakage either to atmosphere or into process depending on the process pressure.

Where double mechanical seal is used?

Double mechanical seals are commonly used in the following circumstances: If the fluid and its vapors are hazardous to the operator or environment, and MUST be contained. When aggressive media are used at high pressures or temperatures. For many polymerizing, sticky media.

What is double acting mechanical seal?

A double mechanical seal is a type of mechanical seal with two primary seals or sets of faces, it can operate in various arrangements with a) a barrier (containment) between the sets of faces or b) a buffer (mixing).

What are types of double mechanical seal?

There are three ways seal faces are configured / arranged in double mechanical seals: Back-to-Back, Tandem, and Face-to-Face. Each configuration has its own strengths which are addressed below.

Mechanical seal working animation types of mechanical seal

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 the difference between barrier fluid and buffer 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 the purpose of a dual lip seal?

(double lip): This design has NO spring and is generally used for sealing a non-pressure medium, such as grease and is used to protect against dirt as well as internal and external media.

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 secondary seal?

Definition of 'secondary sealing'

There is primary sealing of the space between the inner wall of the tank and the floating roof, and secondary sealing above the primary seal. Secondary sealing is a system of wiper seals used in floating roof tanks.

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 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.

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 mechanical seal in pumps?

The mechanical seal acts as a check valve and a slider bearing. The obvious function is that of a check valve to prevent liquid under pressure from leaking out of the pump, or from drawing air into the pump when under vacuum conditions.

What is inboard in mechanical seal?

Inboard Mechanical Seals

The term Inboard seals simply refers to seals that are mounted inside of a pumps stuffing box, to a shaft or sleeve and are mounted independently as individual parts. Unlike Cartridge seals which is a unitized set of rotating, stationary, sleeve and gland components.

How many types of mechanical seals are there?

The Three Types of Mechanical Seals

Three types of mechanical seals are used in process equipment: Cartridge. Component. Air.

How do you select a mechanical seal?

How do you identify mechanical seals?

On the back side of the "seal head" (the end which fits towards the "spring"), measure the inside diameter. This will determine the seal size diameter - which is either the shaft size or the sleeve size that the seal fits over. The front side of the seal usually has a black carbon face.

What is the difference between a static and dynamic seal?

Static seals are usually used when there is no relative motion between mating surfaces. Dynamic seals are the opposite. They are used when there is motion between surfaces. This can be either reciprocating or oscillating motions.

Is a lip seal dynamic or static?

This type of seal is necessarily used for all types of dynamic seal. Lip seals are therefore used in the presence of parts moving against each other in order to obtain an effective seal, limiting abrasion and other problems of deterioration of the seal caused by the rubbing.

What is a buffer fluid?

See Buffer fluid. Buffer fluid. Externally supplied fluid at a pressure lower than the pump-seal-chamber pressure, used as a lubricant and/or diluent in a dual unpressurized seal.

What is seal chamber pressure?

The seal chamber pressure is a function of wear ring clearance as well as size and location of the balance holes. Two Stage Horizontal Pumps. Impeller arrangement can have two. configurations: 1.)

What is the oil of the mechanical seal?

MSHV04 is a lower viscosity inert oil and is typically used as a mechanical seal oil or instrument fill fluid. MSHV06 is also a lower viscosity inert oil and is typically used in the same applications as MSHV04. MSLV27 and MSLV56 are medium viscosity inert oils and are typically used for general purpose lubrication.