outside plant presentation

Kasper Pols

Oplossing in lekdetectie

- 2Date www.leakcontrol.nl

World’s only specialist in Leak Testing based on the Hydrogen Method

Started 1981 by scientists from Linköping Technical University and Chalmers Technical University

First applications for telecom 1985

Business areas:

Outside Plant (Telecom) Industry - instruments Industry - machines Consultancy

Date - 3www.leakcontrol.nl

Some of our customers


ABB SWEAlfa Laval SWE Bosch GER Sabca BEBritish Telecom GBR China Telecom CHNDaimler Chrysler GER Deutsche Telecom GER Electrolux CHN,IND,SWEEricsson Technica HUNFrance Telecom FRA Honeywell NLKenmore Intl GBR, CHN New Zealand Tele. NZL Corus NL Shell NL Akzo Nobel NL Tele Danmark DEN Telemex MEXDutch Marine NLTelstra AUSToyota JPN

Why Hydrogen? The lightest of all molecules Lowest viscosity of all gases (easy to fill,

evacuate and dissipate) Low background (0,5 ppm) Environmentally friendly Much cheaper than helium Non flammable (when diluited 5% in N2)

Non toxic – non corrosive


With the H2 Method leaks can be located in…

Telephone cables Gas pipes Petrol stations Water pipes Gas-filled power cables In-house heating systems



Maintenance crew at work, using Sensistor Leak Detector

Pre-location can be performed manually or with computerised monitoring system

The objective is to find the most suitable point to inject the gas (see example)


› Be sure to have enough of tracer gas for the leak location.

› Connect the tracer gas bottle to the cable.

› Be sure to use 5% Hydrogen in 95% Nitrogen.

› Do not use higher pressure than what is used normally (output from compressor).

› Calculate the volume of the cable from the connection point to the pre-location point.


Connecting the gas bottle


› Check all gas connections for leaks.

› Do not fill the cable with pressure above working pressure (typical 0.6 bar).

Controlling the gas› By checking the gauges (how much gas is used), prediction can be done

to see if gas has reached the leak.

› Duct cable: start the search when gas has reached the predicted leak.

› Directly buried cables: the search can not start until the gas has reached the surface. The time for the gas to surface is depending on ground condition and depth.



Material Depth TimeDry sand 1m 20 minDry soil/wet sand 1m 1 hWet soil/dry clay 1m 4 hWet clay 1m 12 hAsphalt 5cm up to several hoursAsphalt 20cm several hoursConcrete 20cm several hoursNote: The time given for the gas to rise to the surface can vary substantially depending on ground conditions.

Approximate tracer gas consumption /100 meter cable

› Diameter 35mm Ø = 80L (gas volume at 0,6bar relative)





Search the stretch (pipe/cable length) Start at the pre-located leak position, follow the whole

marked stretch, make sure you are on the right location Check the whole duct(s) close to the pre-located leak

position


Be sure to check all joints and cable splits in manholes in the designated search

area.


Typical places where cable leaks can occur

Using the Duct Probe 8712› Use the fan to control the direction of air-flow if necessary


Using the Surface Probe 8612› Be sure to verify the position of the leak


Accessories


Surface Probe

Ground Probe

Duct Probe

Ear-phones

Wheel Unit

Fan

www.leakcontrol.nl

outside plant presentation

Documents

gas volume

gas bottle date

gas connections

tracer gas bottle

bar relative date

customers date

corrosive date

example date