LEAKAGES IN PIPES

STUDY ON FLANGES AND VALVES OF PIPES

FLANGEA flange is an external or internal ridge, or rim

(lip), for strength, or for attachment to another object, as the flange on the end of a pipe .

pipes with flanges can be assembled and disassembled easily. Some type of materials use to manufacture flanges are cast iron, carbon steel, 12mo-steel, al steel .

A flange can also be a plate or ring to form a rim at the end of a pipe when fastened to the pipe.

VALVEA valve is a device that regulates, directs or controls the

flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways.

In an open valve, fluid flows in a direction from higher pressure to lower pressure.

The simplest, and very ancient, valve is simply a freely hinged flap which drops to obstruct fluid (gas or liquid) flow in one direction, but is pushed open by flow in the opposite direction. This is called a check valve, as it prevents or "checks" the flow in one direction.

Valves are also used in the military & transport sectors.

CAUSES : FLANGE LEAKAGE

UNEVEN BOLT STRESS An incorrect tightening/assembly procedure

or difficult access to fasteners can leave some bolts loose while others are over tightened and can crush the gasket.

This can cause in-service leaks, especially in high temperature services when the heavily loaded bolts relax.

CAUSES: FLANGE LEAKAGES

IMPROPER FLANGE ALIGNMENT Flange face parallelism causes uneven

gasket compression, local crushing, and can cause subsequent leakage.

Improper flange centerline alignment can also cause uneven gasket compression and flange leaks.

CAUSES: FLANGE LEAKAGESTHERMAL SHOCK

 Rapid temperature fluctuations can cause flanges to deform temporarily.

This is typically a greater potential problem in high temperature applications.

Temperature variations cannot always be avoided.

Thermal gradients across the flange and cause leakage.

CAUSES: FLANGE LEAKAGESDIRTY OR DAMAGED FLANGE FACESDirt, scale, scratches, protrusions, weld

spatter on gasket seating surfaces, and warped seating surfaces provide leakage paths or can cause uneven gasket compression that can result in flange leakage.

CAUSES: VALVE LEAKAGESOFTEN LARGE DIAMETER BLOCK VALVES ARE STORED ON A

DUSTY CONSTRUCTION SITE WITH NO END COVERS OR ALTERNATIVE PROTECTION FROM AIRBORNE CONTAMINANTS.

VALVE IS NOT FULLY CLOSED

THE VALVE SEALS ARE DAMAGED

SHELL'S SECOND OIL LEAK IN NORTH SEA PIPELINE CAUSED BY RELIEF VALVE

DETECTION : ACOUSTIC LEAK DETECTORS

( SUBSEA LEAK DETECTION TECHNIQUE )

WORKING PRINCIPLE

A pipeline leakage consists in the transition of a fluid from the inside pressure to the lower external pressure.

This creates an acoustic signal due to the turbulence and to the sudden expansion of the fluid mass.

ALD is capable to acquire and process the acoustic data in order to extract this leakage signal from the ambient noise

DETECTION : ACOUSTIC LEAK DETECTORSTHE EQUIPMENT'SThe system is mainly composed by an underwater acoustic sensor, a POD

(underwater electronic unit), a transmission line, a receiving unit and a PC based processing and display software.

The sensor is driven along the pipeline or positioned close to a flange or connection, the receiver puts the operator in condition of identifying an eventual leak signal.

A proprietary software allows to evaluate in real time the signal acquired and its evolution along the track. This software performs analysis of the acquired data from statistic, energetic and a spectral point of view.

The leak signal generated by a leak is mainly composed by ultrasound, the ALD receiver shifts this signal to audible lower frequency generating a “virtual audio” .

DETECTION : ACOUSTIC LEAK DETECTORSADVANTAGESNOT AFFECTED BY CURRENT, TURBITIDY, VISIBILITY,

AMBIENT NOISE

NO NEED TO STOP PRODUCTION

HIGH SENSITIVITY FOR SMALL LEAK DETECTION

100% RELIABILITY: NEVER LEFT BEHIND A LEAKING PIPELINE

RAPIDITY

WORKS ON BURIED PIPELINES

DETECTION : ACOUSTIC LEAK DETECTORSHOW TO DETECT THE LEAKS?The diver handles the sensor and drives it around the flange to be inspected,

data are sent by a soft-cable to the surface receiver.

The ALD operator is in continuous communication with the diver and monitors the result of data processing.

The sensor is neutral in water and very easy to handle, an underwater POD is fixed to the diver safety bottle.

Very accurate inspections of flanges, valves, short pipeline segments.

• THE ALD TECHNOLOGY HAS BEEN MADE AVAILABLE IN A DIVERHAND HELD INSTRUMENT, WITHOUT ANY NEED OF CONNECTIONS TO THE SURFACE THE DIVER OPERATES AUTONOMOUSLY.

DETECTION : ACOUSTIC LEAK DETECTORS

PREVENTIONS: FLANGEBELT

SPECIFICATIONSManufactured in stainless steel (various grades).

The inner lining which can either be tight cells foam or teflon offers a firm watertight seal

The flangebelt can be equipped with a small glass sampling bottle as a sealed leak-detection device.

PREVENTIONS: FLANGEBELTADVANTAGES :Slows down the formation of rust

No corrosion, as rust cannot develop on parts where the flange rests.

Can be used again and again after dismantling.

Long-life expectancy.

Leaks can be detected on isolated flanges

PREVENTIONS: FLANGEBELT

FITTING INSTRUCTIONSPlace the REMOVE FLANGEBELT around the

flange.

Using a screwdriver on the fixation system, tighten the remove flangebelt until perfectly tight.

Optional leak detection system available: small nozzle and/or bottle

PREVENTIONS: REMOVE FLANGEBELT

PREVENTION : AUTOMATIC WATER SHUTOFF VALVE

Automatic water shutoff valves use a water sensor that is placed on the floor to detect water seapage or leakage.

This sensor is connected to to the water valve that controls the water fow.

If a leak is detected, the water valve turns off the water valve and stops the flow of water to the appliance or device.

The signal is actually an electrical signal from the sensing pad to the control unit that activates a magnetic shutoff valve.

PREVENTION : AUTOMATIC WATER SHUTOFF VALVEINSTALLING AN AUTO SHUT OFF VALVEFirst note the top and bottom of the shut off valve, the

bottom has screws and the top has in/out marks.

The red line exits from the last carbon block, enters the "in" on the top of the valve, exits through the "out" on the top of the valve and enters the ro membrane.

The blue line exits the ro membrane as filtered water, goes through the bottom of the valve to the di resin or storage tank. The "in" and "out" portions are interchangeable for the blue line

Thank you