replace steel pipes with PVC?

Old 10-27-05, 02:45 PM
george maxtor
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replace steel pipes with PVC?

i have a clogged bathtub drain. if i use a "draino" type product it will clog again it one week. tried one of thoses bladders that fit on the end of the garden hose. again, clogged in one week.

the drain runs straight down to the basement where it goes into a trap and changes from vertical to horizontal and exits the house. since the toilet and sink in the bathroom are not clogged, i am guessing the problem is only in the bathtub pipe and probably at the trap. i am planning on taking the pipes apart untill i find the clog.

here is my problem.
old house, pipes might be older then the house. they might have been used when installed. appear to be steel. i know they are not lead ,clay or
i have hard water.
since my problem might be the pipes have corroded, and since the pipes might break when i take them apart ,i am going to be prepared to replace the pipes i remove.

is replaceing them with PVC a good idea? can PVC be easily attached to steel, if i have to cut the steel at a joint, or if it breaks at the joint? or will i have to replace all the steel pipe because i cant connect the PVC to steel ? am i better off replaceing the steel pipe with steel ?

i am considering PVC because i belive it will be cheaper and easier to work with.

i remember hearing once that PVC for hot water was against code because it would break, but PVC for a drain was OK.

any suggestions are welcome.

thank you.
Old 10-28-05, 03:44 PM
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Replace pipes with PVC

If you have galv. pipe in your house they are as old as the hills, you have to get it out. PVC is fine. All of your pipe needs to be replaced, but you can do it piece by piece. You can hook the two together with a fernco or mission coupling. Lots of luck.
Old 10-31-05, 01:24 PM
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Originally Posted by george maxtor
i remember hearing once that PVC for hot water was against code because it would break, but PVC for a drain was OK.
You CAN use CPVC for water supply. It's the beige colored stuff.
Old 11-18-05, 09:03 AM
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Because it is easy to work with, lightweight and durable, plastic pipe is popular among do-it-yourselfers. Installation costs are usually lower for plastic materials, but in some areas its use in home plumbing systems is restricted; check on where and how local codes will allow plastic pipe to be used.

Polyethylene and polybutylene plastic pipe is flexible and can be cut with a pocket knife or a special cutter. One of the major advantages of plastic pipe is that it will not rot or corrode.

A disadvantage for some types, such as flexible polyethylene, is that it cannot be used for hot-water lines. Any plastic pipe used to carry drinking water should have the seal of the National Sanitation Foundation.

Following is a list of common plastic pipes and their characteristics.

*Polyvinyl Chloride (PVC) - excellent chemical resistance, good crush resistance and impact strength, fire resistant (self-extinguishing). Is functional up to 120 degrees F in pressure systems and 180 degrees F in non-pressure systems, such as drain, waste and vent (DWV) applications.

Used in pressure supply and drainage systems to carry water for uses such as golf-course sprinklers and agricultural irrigation, and in underground gas-distribution systems, industrial and chemical piping, corrosive fume ducting and crude-oil transportation.

*Chlorinated Polyvinyl Chloride (CPVC) - excellent chemical, crush and fire resistance, high-impact and tensile strength, and is nontoxic; CPVC can be used for hot and cold-water applications. Functions at 180 F in pressure systems and at higher temperatures in low- and non-pressure systems. CPVC does require a special solvent cement different from cement used for other types of plastic welding.

It is used in hot and cold water-supply systems and hot and cold chemical-distribution systems.

*Polyethylene (PE) - excellent chemical and crush resistance. Has high impact strength and flexibility and good low-temperature performance. Functions in temperatures from -65o to 120 degrees F in low-pressure applications and to 200 degrees in non-pressure applications.

PE is used in low-pressure water systems, such as golf-course sprinklers; to carry corrosive liquids and gases; as underground conduits and gas-pipe reliners; in industrial and chemical laboratory drainage systems, and underground gas piping. Perforated PE is used as a corrugated drainage pipe for foundation drainage.

*Polybutylene (PB) - only flexible plastic tubing suitable for use with hot and cold water in pressure systems. PB has excellent chemical resistance to acids and alkalis, but is not suited for fuel oil, gasoline or kerosene distribution systems.

Polybutylene can be joined with heat fusion, flare or compression fittings. However, it is not solvent weldable. Several plastic fitting designs are available for use with PB.

Polybutylene has excellent strength characteristics. Manufacturers of PB claim that should water freeze inside, the tubing will not burst. However, some fittings used with PB will break under ice expansion.

PB is rated to function at 180 F up to 100 psi; higher temperatures can be tolerated with a relatively small reduction in pressure.

*Acrylonitrile-Butadiene-Styrene (ABS) - good chemical resistance, excellent impact strength, especially at low temperatures and maintains rigidity at higher temperatures. Maximum functional temperature is 180 degrees for non-pressure systems.

ABS is used in mobile home and residential drainage systems to provide gas service and as underground electrical conduits.

*Rubber Modified Styrene (SR) - good crush resistance, fair impact strength and moderate chemical resistance. SR is lightweight but brittle at low temperatures. Functions at a maximum of 160 F.

SR is used for drainage and sewage systems, underground downspout drains, underground electrical conduits, septic-tank absorption fields and foundation drains.

*Polypropylene (PP) - excellent chemical resistance, resistant to sulphur-bearing compounds, lightweight, good tensile strength and saltwater resistance. Stronger and more rigid than polyethylene with a higher functioning temperature (190 degrees F), polypropylene is popular as a material for tubular products, such as P-traps, because of its high chemical resistance.

*Polyacetal (ACETAL) - excellent resistance to paraffins and solvents, high resistance to surge fatigue, nontoxic and approved for potable water. ACETAL is used for process systems; solvent handling; agricultural chemicals, crude-oil and natural-gas distribution systems.

Polyacetal is also used to manufacture faucet bonnet and valve stems.

Although there are many types and sizes of plastic pipe available, the most popular for home use is flexible polyethylene pipe with 1/2", 3/4" or 1" inside diameter. This pipe is lightweight and can be cut with an ordinary sharp knife or a fine-toothed hacksaw blade.

When metal pipe is buried underground, care must be taken to drain water before temperatures drop below freezing. Otherwise, both pipe and fittings would rupture when freezing water expands.

These precautions are not necessary with flexible plastic pipe. It can be buried a few inches below the surface or deep enough to protect the pipe against accidental damage from digging or cultivation.

To install flexible plastic pipe, the homeowner simply unrolls a coil of plastic pipe; couplings are not required unless the pipe is cut.

Semi-rigid and rigid plastic pipe, which is sold in 10' to 20' lengths, does require coupling.

Depending on the chemical composition of the pipe, pieces are joined with an insert coupler using metal straps to hold the coupling to each section of pipe or with a coupler that is sealed with a pipe cement. This cement creates a chemically fused bond between coupling and pipe that is as strong as the pipe itself. The exception is PE, which cannot be welded with cement.

Most plastic pipe can be joined with and worked into metal plumbing with the use of proper adapters or transition fittings.

Rapid technical advances in the manufacture and use of plastic pipe have made it imperative for consumers to follow the manufacturers' information on use, installation and pressure ratings of the pipe and fittings.

One area where these changes are most evident is in supply tubing. Supply tubing has gone through a metamorphosis from copper to corrugated copper to polybutylene and vinyl supply tube. Vinyl supply tubing is easy to hook up, and with its flexible "give" will alleviate a mild water-hammer condition created by many single-lever faucets with quick shutoff. Stainless-steel braided flexible supply connectors are another form of supply tubing. Stainless-steel braiding encases a nontoxic synthetic polymer or neoprene rubber core suitable for both hot and cold water.

Manufacturer claims include high-burst pressure ratings (1,500 psi to more than 2,400 psi), resistance to embrittling, and crimping on fittings that won't creep or blow off.

No cutting or flaring is involved which eliminates pipe bending, soldering and special tools.

Stainless steel braided connectors are available for faucets and toilets as well as for water heaters, water softeners, dish and clothes washers, hot tubs, etc.

Similar connectors use nylon braiding which offers a reduced burst pressure in the 600 psi range.

Plumbing fixtures are equipped with either a P or S trap, which is frequently fitted with a clean-out plug on the bottom. The trap bend holds water which prevents odors from backing up into the home.
Drum and bottle-type traps for bathtubs or kitchen sinks consist of a cylindrical metal box or settling basin attached to the waste pipe. They are generally provided with a screw-cap cover that can be removed when cleaning is necessary.
In most areas 1-1/4" chrome-plated brass traps are used in lavatory drains, and satin-finished or nickel-plated brass 1-1/2" traps are standard equipment on residential kitchen sinks. (Satin finish is unpolished chrome-plated tubular).
Plastic P and J traps can be used in retrofit as well as new plumbing work with adapters and transitional couplings to connect plastic with other materials.
Corrugated flexible plastic drain is useful when installing new sinks or vanities with older drain systems. Many times the drain from a new installation will not line up with the old drain pipe. Corrugated, plastic drain pipe allows the d-i-yer to connect misalignments by as much as several inches.

When selecting pipe-joint compound, you need to know what the pipe will carry after installation-natural gas, oil, gasoline, water, or any other fluids or gases.

An advantage of commercially prepared pipe joint compound is its ability to seal all joints, yet make disassembly easy, to prevent seizure of parts by rust and corrosion.

Pipe-joint compounds come in 1-oz. tubes up to brush-on cans or 50-gal. drums.

One form of pipe-joint compound is Teflon tape, which comes in rolls; standard widths are 1/4", 1/2" and 3/4", and lengths range from 30' to over 100'.

Special compounds are also available that are fast drying and hard setting.

Certain plastics are attacked by pipe compounds so be sure the compound is specifically recommended for any plastic material it is used with.

*Note: Do not use plumbers putty on any type of plastic pipes. You need something that contains no oils, due to the fact they eat at plastic.


Plastic fittings for plastic pipe, metal fittings for plastic pipe and fittings for connecting (transmitting) plastic to metal pipe are available in threaded, insert, compression and solvent weldable types.

Threaded plastic fittings thread exactly like metal fittings; however, special transition fittings should be used to connect plastic to metal pipe in hot and cold water systems to prevent leaks caused by the different expansion rates of plastic and metals.

Insert fittings are sometimes used with flexible plastic pipe such as polyethylene. Insert fittings are inserted into the pipe and sealed with an adjustable clamp.

Solvent-weld fittings have specially formed sockets into which plastic pipe is inserted. Fitting and pipe are bonded by a chemical weld using the solvent or cement compatible with the type of plastic being connected.

Manufacturer's recommendations should be followed in making such joints. When done properly, these joints form a permanent weld stronger than the pipe itself.

This information has been composed from my past experiences working with plastic and metal pipes, and reference information has been obtained from the National Retail Hardware Association (NRHA). Neither myself, nor the NRHA, can be held responsible for damages or injuries resulting from the use of the information.

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