Why seal flushing is required?

The purpose of the maintenance procedure is to flush any debris from between the seal faces. That debris may have come from particulates in the process fluid, corrosion from aging piping, or metal from an abraded pump volute or impeller.

What is quenching in mechanical seal?

Quench is the term used for an arrangement that applies an unpressurised external fluid to a mechanical seal's outboard faces. The quench liquid can assume the following tasks: Absorption/removal of the seal's leakage. Monitoring of the mechanical seal's leakage rate. Lubrication/cooling of the stand-by seal.

What is the main purpose of a mechanical seal?

1 INTRODUCTION. Mechanical seals are devices that are used to provide a seal at the point of entry or exit of a rotating shaft. Typically it is used to prevent the leakage of one high pressure fluid into a lower pressure fluid.

Do mechanical seals need lubrication?

Lubrication is necessary for proper mechanical seal installation. Lack thereof can damage o-rings or rubber bellows on the seal, causing them to tear, or roll.

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).

Kates - API 682 Seal Flush Plans

What is a seal flush?

The definition of a flush is a “fluid which is introduced into the seal chamber on the process fluid side in close proximity to the seal faces and typically used for cooling and lubricating the seal faces.

How does seal flush work?

This method consists of a minimal flow of a clean, relatively cool liquid (usually water) from an external source injected into the seal gland flush connection at a pressure higher than the pump seal chamber pressure. The external flushing liquid flows past the seal and into the pump, mixing with the pumped fluid.

What causes mechanical seal failure?

A mechanical seal might fail due to poor lubrication, or no lubrication at all. When there is no liquid around the seal it will be subjected to increased amounts of friction which will increase the temperature inside the pump.

What is the most common failure of a seal?

Improper installation is probably the most common cause of seal failure. Using the right tools is critical to prevent seals from being installed in the wrong direction or becoming damaged during installation.

What causes seal leaks?

If there are no fluids available to lubricate, the seal runs dry which causes extra friction and heat. The seal will burn or melt and become damaged, which causes fluid leakage due to the pressure. Even a few seconds of dry running can cause heat cracks or blisters, which leads to a leaking pump shaft seal.

How many types of mechanical seals are there?

8 Types of Component Mechanical Seals.

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).

Do mechanical seals require seal water?

Mechanical seals require clean water, or other compatible liquid, for the lubrication of the seal faces. The faces in a typical mechanical seal are lubricated with a boundary layer of gas or liquid between the faces.

What is a flushing pump?

Flush pumps are used for low lubricity liquids (Deionized water) and liquids with elevated temperatures. Like all standard plunger pumps, a flushed manifold pump is configured with an inlet and outlet port.

What is API plan 52?

API Seal Plan 52 utilizes a reservoir and circulates an unpressurized buffer fluid between the inboard and outboard seals. To provide positive circulation through the support system and into the seal, a pumping ring is employed.

What is seal plan 53B?

API Plan 53B circulates a pressurized barrier fluid between the inboard and outboard seals. The source of pressurization is a bladder accumulator. Plan 53B has the advantage of not allowing gas absorption into the barrier fluid which may allow for operation at higher pressures than Plan 53A.

What is the purpose of seal water?

The seal water system provides lubrication and flushing action of clean water for the mechanical seals and packing boxes in the sewage pumps. Water pressure is forced into the stuffing box thereby flushing away contaminants.

How much water does a seal need?

Like all marine mammals, seals get all the water they need from their food. Their bodies are very efficient at removing and recycling water from their food. They avoid drinking sea water; if a seal drinks too much sea water it can become seriously sick.

What does seal water mean?

Water used to prevent wastewater or dirt from reaching moving parts. Sealing water is at a higher pressure than the wastewater it is keeping out of a mechanical device.

What is double 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 is reverse balance seal?

Product Description. Reversed Balanced Pusher seals. Multiple spring Reversed Balance Mechanical Seals are externally mounted internally balanced multiple spring seals. the unique feature of this type of seals is that, it eleminated the shaft step or sleeves for balancing.

What is a pusher seal?

A pusher-type seal consists of a primary sealing ring assembled with an 'O' ring and springs which force the sealing liquid across the face and keep it from leaking to the ID side of the seal.

Why spring is used in mechanical seal?

Various types of spring mechanisms are used in mechanical seals to supply the pressure to keep the stationary and rotating seal faces together. They can be divided into four general types: single spring, multiple spring, wave spring and metal bellows.

What is a Type 1 mechanical seal?

Suitable for a wide range of service conditions ranging from water and steam to chemicals and corrosive materials, the Type 1 mechanical seal is ideal for use in pumps, mixers, blenders, agitators, air compressors, blowers, fans and other rotary shaft equipment.

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.