Gas Piping Systems Flashcards
7 cards from real Plumbing practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Gas Piping Systems flashcards as text
What is the safe, approved method for detecting a gas leak at a fitting or connection?
Answer: Apply soapy water and watch for bubbles
Applying an approved leak detection solution or soapy water to fittings and observing for bubbles is the safe standard method — open flames are extremely dangerous.
What additive is mixed into natural gas to give it its distinctive warning odor?
Answer: Mercaptan (ethanethiol)
Mercaptan (ethanethiol) is added to otherwise odorless natural gas so people can detect leaks by smell before concentrations reach dangerous levels.
What is the maximum allowed length for a flexible gas connector hose to a residential appliance?
Answer: 6 feet
Most codes limit flexible gas connectors to 6 feet maximum to reduce the risk of mechanical damage, kinking, or accidental disconnection.
Why must CSST (corrugated stainless steel tubing) gas piping be bonded to the electrical grounding system?
Answer: To protect the thin stainless steel walls from damage caused by lightning-induced electrical arcing
CSST's thin corrugated stainless steel walls are vulnerable to arcing from indirect lightning strikes, which can burn through the material and cause gas leaks; bonding diverts this energy safely.
What action must be completed before a gas system is returned to service after any repair?
Answer: Pressure test the system and inspect all connections for leaks
After any gas piping repair, the system must be pressure tested and all joints inspected for leaks before the gas supply is restored and the system is placed back in service.
Which appliance connection typically REQUIRES a flexible gas connector rather than rigid pipe?
Answer: Gas range/stove
A gas range requires a flexible connector because it is a movable appliance that must be pulled out periodically for cleaning and service, making rigid connections impractical and prone to damage.
What is the required pitch for a horizontal gas supply line to direct condensate toward a drip leg?
Answer: 1/4 inch per foot downward toward the drip leg
Horizontal gas lines should slope 1/4 inch per foot downward toward a drip leg so that moisture and condensate drain to the trap rather than entering appliance controls.