Frequently Asked Questions (FAQ) about Plumbing Pipes

Friday, January 17, 2020

Plumbing is not a hot topic of conversation at cocktail parties but, when the toilet backs up or a water pipe springs a leak, how the plumbing in your home has been installed and maintained becomes much more interesting. Here’s links with answers to some of our most often asked questions about plumbing pipes:

How can I tell what type of plumbing pipe I have?

 Are plastic pipes (PVC, CPVC, and PEX) safe for drinking water? 

What do the ABS, PVC, CPVC, PB, and PEX plumbing pipe names mean? 

What are the abandoned pipes sticking out of the wall in my house? 

What are the pipes on my roof? 

Why is it a problem when a trap under a sink is installed backwards? 

 How can I protect my pipes to keep them from bursting during a hard winter freeze in North Florida?

 Can galvanized steel pipe still be used for new water lines in a house? 

What are the code requirements for plumbing vent terminations?

What are the code requirements for layout of drain piping under sinks?

What causes a gurgling sound when a bathtub or sink drains? 

 How can I tell if I have cast iron pipes in my house? 

 Is it alright to have a shut-off valve on both the hot and cold water pipes at a water heater?

 Why can't a sanitary tee be used for a horizontal-to-horizontal drain pipe connection? 

 Is a washing machine drain hose required to be secured at the standpipe?

What is the difference between green and white sewer drain pipes?

 How can I tell the difference between Corrugated Stainless Steel Tubing (CSST) and a Flexible Appliance Connector (FAC)?

 What is a "combination waste and vent" in a plumbing system? 

 Does a "QEST" brand mark on pipe mean that it is polbutylene (PB)?

 What is a building trap?  

 What is a galvanized nipple?

 What are the pipes sticking out near my water valves?

What is an "S-Trap" under my sink? Why is it a problem? 

What is a P-trap?  

 Can PEX pipe be installed outside?  

 Is PEX pipe freeze resistant?

 How do you accurately find a broken water pipe leak under the floor slab?

 What is the difference between water pipe and sewage (waste) pipe? 

 What is the average life expectancy of PEX pipe? 

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What type of water supply and drain (DWV) pipes were commonly used in older houses?

 What type water supply and drain (DWV) pipes were commonly used for 1950s residential plumbing?

 What type water supply and drain (DWV) pipes were commonly used for 1960s residential plumbing? 

 What type water supply and drain (DWV) pipes were commonly used for 1970s residential plumbing? 

What type water supply and drain (DWV) pipes were commonly used for 1980s residential plumbing?

 What type water supply and drain (DWV) pipes were commonly used for 1990s residential plumbing? 

• What type of water supply and drain (DWV) pipes were commonly used in the 2000s? 

• What type of water supply and drain (DWV) pipes are commonly used today?

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  What is the average life expectancy of galvanized steel pipe? 

• What is the average life expectancy of ABS pipe

What is the average life expectancy of copper pipe? 

What is the average life expectancy of PVC pipe? 

 What is the average life expectancy of cast iron pipe?

 Is a hot water faucet handle required to be on the left? 

 Why is sunlight exposure bad for PVC pipe?

 Why can't PVC be used for water pipe inside a house?

 What is a dielectric union? 

 What's that powdery crust on the pipe connections at the water heater? 

 Can I make a trap under the sink from straight pipe and 90º elbows?  

 What type of white plastic pipe has the marking CP-112-P in red letters? 

 If all the plumbing drains have water in them and you can still smell sewer gas, what's causing the problem?  

 Why is there a flexible accordion pipe under the sink? 

 What is the difference between PVC and ABS plumbing pipe?  

 What is the difference between water service pipe and water supply pipe?  

 Why is old galvanized steel water pipe a problem for homebuyers?

 What does polybutylene pipe look like? Why is it a problem? 

• Which water pipes are an insurance problem and possibly uninsurable?

• Can PVC pipe be used for indoor plumbing? 

• Should I buy a house with galvanized steel water pipes?

• Can you connect CPVC pipe directly to a gas water heater?   

• Should I use a dielectric union or brass nipple to connect copper tubing and galvanized steel pipe?

• What problems are caused by connecting copper pipe/tubing directly to galvanized steel pipe? 

• Is pipe insulation flammable?

• What does the Aqua-Rex Water Conditioner do? 

Why is some PVC pipe black?

What are the requirements for installing a gas appliance connector? 

• Why is Orangeburg sewer pipe a problem and how do I know if I have it? 

• What is the average life expectancy of Orangeburg (bituminous fiber) pipe? 

What is plumbing venting? When was it first required for plumbing drain systems? 

• Can gas piping be installed in a supply or return duct or plenum? 

Does a home inspector check and test shut-off valves? 

 Will a sprinkler system work without a vacuum breaker (backflow preventer)? 

What devices are code approved for backflow prevention at a sprinkler (lawn irrigation) system? 

• How can I find out what type of water pipe runs underground from the water meter to the house (service pipe)? 

 Where do I find the main water shut-off valve for my condominium? 

• Does code require water pipes in the attic to be insulated? 

• Does code require water pipes in a crawl space to be insulated? 

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