Pipework & Meters Flashcards
6 cards from real ACS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Pipework & Meters flashcards as text
What is the correct procedure for locating a gas leak using a leak detection fluid?
Answer: Pressurise the installation and apply the fluid to each joint and connection, observing for bubble formation that indicates a leak
Leak detection fluid (or electronic detector) is applied to pressurised joints while gas is flowing; bubbles indicate a leak at that point — a systematic approach from meter to appliance is used.
What is a 'gas pressure governor' and where is it typically located?
Answer: A device that reduces and regulates the gas pressure from the distribution mains to the correct operating pressure for domestic appliances, typically located in or adjacent to the meter box
The gas pressure governor (regulator) reduces the relatively high distribution network pressure to approximately 21 mbar for domestic use, maintaining a consistent supply pressure regardless of network fluctuations.
What is the permitted working pressure for a domestic low-pressure gas installation in Great Britain?
Answer: 21 mbar
Domestic gas in Great Britain is supplied at a nominal working pressure of 21 mbar; appliances are designed to operate at this pressure, and significant deviations indicate a fault in the supply.
What does a U-gauge (U-tube manometer) measure in gas engineering?
Answer: Gas pressure in millibars by comparing the height difference of water columns in a U-shaped tube
A U-gauge uses the hydrostatic pressure of a water column to measure low gas pressures in millibars — a simple and reliable instrument for checking standing and working pressure.
What precaution must be taken before soldering copper gas pipework joints inside an occupied building?
Answer: Isolate and purge the gas from the pipe section to be soldered, ensure adequate ventilation, use a fire blanket behind the joint, and have a fire extinguisher present
Soldering (hot work) in a building requires gas isolation and purging to prevent ignition of residual gas, fire protection, and adequate ventilation — soldering on a live gas pipe is extremely dangerous.
What does the term 'dead leg' mean in gas pipework?
Answer: A section of gas pipework that terminates in an unused capped-off fitting, with no appliance connected, which retains dead gas in the line
A dead leg is a capped pipe run left in the installation from a previous appliance — it retains gas in the unused section and represents an unnecessary length of pressurised pipe that should ideally be removed.