WHAT IS THE DIFFERENCE BETWEEN PVC, CPVC, ABS and other types of pipe?

Generally speaking, the main types of plastic pipe fall into one of the following categories: 

PVC – This stands for Polymerized Vinyl Chloride (unchlorinated); it is a thermoplastic polymer and is generally not approved for potable water. It is biologically and chemically resistant (to most compounds) and is the leading material used in landscape and garden irrigation supply lines, ponds, pools and water gardens.

CPVC – This stands for Chlorinated Poly Vinyl Chloride; it is essentially PVC that has been chlorinated via a chlorination reaction process.  It is also a thermoplastic polymer and is generally non-toxic due to the nature of the manufacturing process.  It is also resistant to many acids, bases, salts, paraffinic hydrocarbons, halogens and alcohols. It is not generally resistant to solvents, aromatics and some chlorinated hydrocarbons.  It is one of the leading materials used in potable water systems for hoe and industry.

ABS – This stands for Acrylonitrile Butadiean Styrene; it is generally suitable for conveyance of potable water, slurries and chemicals, and is also used for chilled water applications and compressed airline systems. 

PP – This stands for PolyPropylene; it is generally used for potable waters, food handling, compressed air lines and for some uses in the pharmaceutical and chemical industries.  It is generally resistant to chemical damage, but is not generally resistant to UV radiation and should be protected when being used outdoors or in moderate to heavy sunlight applications.

PE/PEX – This stands for PolyEthelene.  PE is generally used as supply pipe in commercial and residential irrigation systems and drip irrigation systems.  PEX is simply a cross-linked polyethylene. Through one of several processes, links between the polyethylene molecules are formed to create bridges (thus the term "cross-linked). The resulting material is more durable under temperature extremes, making PEX an excellent material for hot water and other applications. (PEX) is increasingly being used to replace copper and traditional plastic piping for transporting both hot and cold water.

PVC Pipe vs. PVC Hose or tubing??

There are many different “terms” and “names” used for the products that we sell on our website.  Obviously, we like the term “flexible PVC” – we named our website after it!  But with all the terms that are used in the industry, at the plumbing supply house or at your local home center, we thought it might help if we explained some of the terms that are used, at least the way we understand them.

At FlexiblePVC.net, we sell flexible pipe, hose and tubing – nothing rigid.  We sell only flexible hose or pipe, not rigid pipe.  Rigid pipe (or “stick” pipe as it is sometimes referred to) is generally used to describe an item that is relatively non-flexible or rigid in nature, and that does not bend easily or was not produced to be bent.  In order to get “rigid pipe” to go around bends, one must use a fitting or a series of fittings. 

At FlexiblePVC.net we sell flexible products that are called pipe, hose or tubing. Since everyone has a slightly different definition of these terms, we try to use them as follows to eliminate any confusion. 

Flexible pipe or hose easily bends and in most cases can be used with a minimum of fittings, or none at all.  Unlike “rigid” or “stick” pipe or hose, it can go around bends and corners without being heated and without the use of extraordinary measures which may actually damage the product.

When you see the word flexible pipe used to describe one of our flexible PVC products, it means you are looking at a product that is used with PVC pipe fittings that glue onto the exterior of the pipe, using approved solvents and cements.   All of our flexible PVC pipe is meant to be used with glue-on fittings, not a “barbed” or “insert” fitting. While these types of fittings may actually work, the product was not designed with this use in mind.  Our flexible pipe may actually work if you use these fittings, but it may not function as well as you would expect as a result.

When you see the word flexible hose or tubing used to describe one of our flexible PVC products, it means that you are looking at a product that is meant to be used with “barb” or “insert fittings” and is not meant for use with the glue-on style fittings referenced above. This type of flexible hose or tubing is not meant to be glued into PVC fittings, instead you use a barbed or insert fitting, with a clamp to secure the connection – not glue.

We realize that these terms are thrown around in the industry referring to all sorts of different product.  We just want you know what WE mean when use them, so we can get your order right, the first time. Please keep these distinctions in mind when you are ordering product on our site.  It will help us to be certain to get you exactly what you expected, without delays and questions.

The Greenest PVC Glue on the market today

Gorilla PVC Glue

Much like the names or terms used for our products (Flexible PVC), the terms for the glues and primers are used in many different ways and contexts as well.  Here is the best of the information that we have been able to find concerning PVC glues and primers.  PLEASE BE CERTAIN that the product you purchase is specified for use with PVC pipe (even better if it states it is for use with flexible PVC pipe).  There are cleaners and glues made specifically for PVC, for CPVC and for ABS and they generally do not play well together.  As always, it is best to read the instructions on the glue/primer that you purchase for use to ensure it will work with your product, and that you are utilizing it properly.

All pipe surfaces intending to be glued should always be thoroughly cleaned with PVC pipe cleaner before gluing.  Oils, dust and dirt accumulate during the manufacturing process which can affect the holding power of the cement/glue if the pipe is not properly cleaned.

We are often asked about the differences between the primer, cleaner and cement/glue products on the market.  Essentially there are three main types of PVC pipe primer/cleaners: 

PVC  cleaner – This is a cleaner ONLY and it is generally formulated to remove oil, grease, dirt and any other foreign materials that may exist on the surface of the product remaining from the manufacturing process.  It does not prepare or soften the pipe in any way in preparation for gluing or assembly.

PVC primer/cleaner – This is a “hybrid” or combination product which contains both a cleaner and a softening primer that helps to prepare/soften the pipe surface to allow the solvent cement to penetrate more effectively.

PVC primer – This product contains more aggressive solvents that are intended only to soften the pipe surface to allow the solvent cement to penetrate more effectively.  The pipe should be cleaned properly before using a primer only.  Local codes often require the use of a primer when working with PVC pipe, and sometimes a certain type (i.e. purple primer) is required.  If you have questions, check with your local code authorities. 

Much like the primer used, it is extremely important to select the proper solvent cement (glue) for your flexible PVC product as well.  Generally speaking, there are several different types of solvent cements available, as follows:

Flexible PVC cements are specifically designed with flexible PVC pipe in mind, work well with the vibrations and pressure associated with flexible PVC pipe and should be your first choice if available.

PVC cements should be used only for PVC pipe and fittings, but generally will work well with flexible PVC products. (Be certain that the manufacturer does not specifically exclude flexible PVC products in the “uses” information on the product).

CPVC cements should be used only for CPVC pipe and fittings and do not work well with flexible PVC products.

ABS cements should be used for ABS pipe and fittings and do not work well with flexible PVC products.

All-purpose cements – Most of the all-purpose cements on the market can be used on all schedules and classes of ABS, PVC and CPVC pipe; however we have heard of some brands of all-purpose cement that specifically state that it is not for use with flexible PVC pipe, so be careful in your selection.

Most good solvent cements/glues have an applicator/dauber built into the lid of the container. This applicator/dauber can be used to apply cement/glue to pipe sizes up to about 3" in diameter. Generally speaking, most manufacturers recommend the use of an applicator brush measuring at least one-half the size of your pipe diameter if the diameter of the pipe is greater than 3" to allow proper coverage and allow enough time.

Most manufacturers recommend that their solvent cements/glues be applied in temperatures between about 40 degrees and 90 degrees Fahrenheit.  A good rule of thumb below or above those temperatures is to only use the solvent cement/glue if the glue is easily stirred and not lumpy or coagulated. If the solvent cement/glue is frozen, lumpy or will freeze during application or curing, do NOT apply.   Remember that outside the recommended temperature ranges, additional handling and longer curing times apply – please refer to your manufacturers’ recommendations if you have this need.

Drying/curing times also vary by manufacturer.  Generally speaking, with temperatures between 40 and 90 degrees Fahrenheit, we’ve seen recommended cure times like the following:

Pipe diameter up to 3 inch = 10 minutes

Pipe diameter 4 to 5 inches = 30 minutes

Pipe diameter 6 to 8 inches = 90 minutes

Again, these vary by climate and also by manufacturer, and most manufacturers agree that you should add additional curing time when using flexible PVC products.  Check also with the specifications on the container for use with flexible PVC products.

IMPORTANT NOTE - The primer used is intended to soften the pipe surface and prepare it for the application of the cement/glue.  It is therefore important to apply your solvent cement/glue to the pipe and fittings while the primer is still wet in order to achieve maximum bonding strength.

Measuring and cutting your Non Metallic Liquid Tight PVC Electrical Conduit.

Liquid tight electrical conduit comes in a variety of different wall thicknesses and flexibilities.   While there are a number of tools on the market for cutting non-metallic liquid tight, unless you are a professional and will be using these tools frequently, you probably want to resort to the time-trusted method below to measure and cut your PVC electrical conduit.

Let's Do It!

1.   You'll need to equip yourself with a tape measure (a ruler will work for very short distances), a ball of string or cord if you will be measuring around corners or obstructions, paper and a pencil or pen, a marking pen, light colored tape, a hacksaw with a fine cutting blade, a bench vise or other clamping device and a fine metal file.

2.  Time to measure.  If you are running your liquid tight conduit in a straight line only with no bends or obstructions, simply measure the distance between the two points and write your measurement down on the paper.  If you must go around corners, measure all of your straight sections first, noting the measurements on your paper.  Use the string to measure the distance around your corners and measure the length of the string with your tape measure once you straighten the string out.  Remember that your string must be stretched so as to mimic the center of your conduit.  If you are going over or around obstructions, use your string to measure as indicated above. 

3.   Measure against your PVC conduit and place a piece of light colored tape over the area where you need to cut.  Measure again once the tape is in place and draw your line to cut directly on the light colored tape.

4.   Place your conduit in a vise or otherwise secure the conduit for cutting.

5.  Using your hacksaw with the fine cutting blade, carefully cut your conduit along the line you've drawn on your tape.  Be certain to follow your line all the way around the conduit to get a uniform and straight cut.

6.  Remove your conduit from the vise and using a fine metal file, file the ends of your conduit lightly to remove any burrs or inconsistencies remaining from the cutting process.

How to Measure Schedule 40 Flex PVC Pipe

Measure Twice; Buy Once

One of the most frequent questions we get, and the reason for almost every product return to our site, is because the “common sense method” of measuring does not really apply when it comes to Schedule 40 flexible PVC pipe.  The “Pipe Schedules” were constructed by someone undoubtedly in a bureaucratic position, not one using common sense measuring techniques.  It is quite easy to measure across your pipe, but that is where the “easy” ends.  So we say, Measure twice, buy once” and you’ll get what you need the first time.

Someone once sent us the following email about bureaucracy and specifications (source unknown):

RFQ SPECIFICATION WAP-007

PAGE 1 OF 1

PIPING SPECIFICATIONS

All pipe is to be made of a long hole, surrounded by metal centered around the hole. 

All pipe is to be hollow throughout the entire length.

All pipe is to be constructed of the very best quality, preferably tubular in nature.

All pipe specified as “acid-free” must be constructed of acid-free metal.

Outer diameter of all pipes must exceed inner diameter.

All pipe is to be supplied without rust regardless of material.

All pipe over 500 feet in length must have the words “Long Pipe: clearly painted on each end so that the pipe fitter will know that it is a long pipe. 

The above proves why bureaucracies don’t do a good job of creating specifications, but unfortunately, flexible pipe sizes are made in accordance with and to the tolerances of the Schedule 40 pipe specifications.

The standards or “schedules” and sizes work like this.  The outside diameter of a single “nominal” pipe size is kept constant.  So when you are buying a fitting for a Schedule 40 pipe, the outside diameter of the pipe and the fitting size will always be the same.  This is the reason for the “schedules” – so that fittings and pipe can easily match across a broad spectrum of manufacturing, and within “acceptable” tolerance and standards.  So the outside diameter remains constant, and as a result the inside diameter of a pipe will depend on the "schedule" or the thickness of the pipe. The schedule and the actual thickness of a pipe varies with the size of the pipe. 

WHAT DOES THAT ALL MEAN?

OK, let’s cut through the fog here.  It means that you need always need to measure the OUTSIDE (O.D.) diameter of your flex PVC Schedule 40 pipe…

…and then compare that measurement to the following chart in order to order/receive the correct size.  We know, this does not pass the “common sense test”, but it’s the way the industry works…and it will keep you from ordering the wrong size flexible PVC pipe!  We know this is confusing, if you have questions on what size flex PVC pipe or fittings to use, call or email us any time!

PLEASE NOTE – Flexible PVC pipe is NOT meant to be used with fittings that fit INSIDE the pipe, sometimes called barbed fittings, friction fittings or insert fittings.  While these fittings MAY fit and MAY work, we do not recommend their use, nor do we guarantee that our flex PVC pipe will fit these fittings.

PLEASE NOTE – the sizes listed in the chart above are for reference only, and tolerances in the standard allow for deviations in size and diameter of +/- 10%.

Why Choose Flexible PVC instead of Rigid PVC Pipe

Well, to us, it’s quite obvious…..flexible PVC pipe is a pliable PVC pipe that is ideal for situations where rigid pipe is either not practical or desirable. Strong and long-lasting, flex PVC pipe can be used for pools, spas, water gardens  and as a general part of non-potable water systems i.e. hooking up washing machines, pumping waste water, etc.

Flex PVC pipe simplifies most plumbing installations. Because the pipe is flexible, it can easily be routed in any direction, and can be used in areas where space is limited or in other applications that simply would not accommodate a rigid pipe (i.e. tight curves). Flex PVC pipe accepts standard Schedule 40 solvent weld fittings - the fittings used for rigid pipe, so the fittings are readily available, easy to fit and no special tools are needed for the installation.

Storing flex PVC pipe is easy as compared with rigid or “stick” pipe. It can be easily coiled and stored in just about any type of container, or not container at all.  It is considerably less awkward to store than rigid lengths of pipe which can only be stored straight.

Another benefit to the use of flex PVC pipe is the ease of cutting the pipe. Special tools are often not required, as many sizes of flex PVC can be cut with a strong pair of shears or utility knife. Trimming can be accomplished in a matter of seconds and does not require the effort needed to trim a piece of rigid pipe, allowing the job to be completed more quickly and efficiently.

Flex PVC pipe is resistant to mildew and relatively resistant to sunlight, although it is usually not recommended to leave the pipe exposed to direct sunlight for long periods of time.   This makes flex PVC pipe great for use in swimming pool, pond, water garden and agricultural applications.