FPT = Female Pipe Thread
FPT (or FNPT) is where the threads are on the inside of a fitting. This allows a MPT, or Male Pipe Thread part to screw into the female piece. All of our FPT parts are in NPT, National Pipe Thread, which is the type of threading used in the USA.
MPT = Male Pipe Thread
MPT (or MNPT) is where the threads are on the outside of a fitting. This allows the MPT to screw into the matching FPT size. All of our MPT parts are NPT, National Pipe Thread, which is the type of threading used in the USA. Don't use Teflon tape, teflon paste, or pipe dope with PVC threaded connections. Use a sealing compound that is compatible to plastics.
Slip fittings are designed to allow the PVC pipe to slide into the fitting, or 'slip into' if you will. This type of connection makes for quick and easy assembly of complex piping. The slip end of the a slightly larger than PVC pipe so the pipe can be inserted into the fitting.
The end connection of a fitting that is to be assembled into another fitting is called the 'Spigot'. The spigot end of a fitting has the same outside diameter as pipe. The common female connection of PVC fittings is referred to as the socket or hub, and the spigot end of a fitting can be inserted into a hub or socket.
Can PVC be used with gasoline?
Gasoline or many other liquids do not chemically affect PVC. However using PVC pipe and fittings in system handling dangerous liquids requires the design/builder to consider the consequences that may result if there is a failure, or rupture. Physical properties, temperature and user knowledge are only some considerations that must be made. It is NOT recommended.
PVC is more than 60-percent derived from salt, one of the most plentiful resources on earth. The low petroleum content gives the material excellent flame resistant properties. Advances in PVC formulations have made today’s products especially durable, saving on replacement materials and requiring less maintenance over their useful lives. The smooth surfaces of PVC pipe and fittings provide less resistance to fluids flowing through them, requiring less energy to maintain the flow. The corrosion resistance will maintain these excellent surfaces throughout the product’s life. Because it is a thermoplastic, PVC can be recycled and manufacturers commonly recycle pre-consumer material. A 1995 study by the American Society of Mechanical Engineers (ASME) analyzing emissions for nearly 170 different combustion facilities found no statistical relationship between the amount of chlorine (vinyl) in the waste stream and the amount of dioxin emitted from an incinerator. The study did find that the incinerator design and operating conditions – primarily temperature – were keys to controlling dioxin. EPA regulations are forcing reductions in dioxin emissions by addressing operator controls.
Leak-Free PVC Joints
The most important aspects of proper solvent joining of PVC pipe and fittings are:
1. Choosing the correct primers and solvent cements
2. Using the correct size applicator.
3. Using proper procedures for solvent cementing PVC.
Lasco has more detailed information for leak-free joints online at: http://www.lascofittings.com/solventcementingprocedure
The Do's and Don'ts of Aseembling Threaded Plastic Fittings
Today, there are millions of miles of plastic piping with threaded fittings, providing reliable, leak-free service. However, a tiny percentage of those threaded plastic fittings may leak or break. The reason for this is improper assembly of threaded joints. Here are some of the Do's and Don'ts of PVC joint assembly.
Don't over-tighten joints by giving them "one more turn to be sure."
Do finger tighten plus one or two turns- No More.
Don't wrap Teflon tape or Teflon paste or pipe dope to add bulk to or to lubricate the joint.
Do use a sealant for threaded joints.
Don't use "stronger" Schedule 80 threaded fittings on the assumption that they may solve the problem of splitting through over-tightening.
Do use only Schedule 40 threaded fittings with Schedule 40 pipe and fittings.
For more information visit: http://www.lascofittings.com/threads
What colors are used for PVC pipe, and are they color coded?
Although PVC materials can be made in many colors and there is some pattern to what the industry has done, no established color coding exists. The earliest PVC piping was made in industrial gray, and that product line is still very active. Much of the PVC irrigation piping is white. Most PVC water piping is white, but there have been some manufacturers who use blue as a means to distinguish their product line. Many PVC sewer products are green. Much DWV piping is white, but certain manufacturers have opted for beige or buff colors.
What are the markings on PVC pipe?
The outside of PVC pipe must be labeled as follows:
• The manufacturer's name or trademark
• The standard to which it conforms
• Pipe size
• Material designation code
• DWV if for drainage
• Pressure rating if for pressure
• SDR number or schedule number
• If the pipe is for potable water, a laboratory seal or mark attesting to suitability for potable water
For those standards that cover several products, there must be additional markings to indicate the pipe stiffness number, the SDR, the EB or DB number. A certifier's mark may also be on the pipe.
What are the temperature limitations of PVC pipe?
The maximum use temperature for PVC pressure pipe is 140 degrees F. PVC DWV piping readily withstands the hot and cold water discharges that are normally associated with plumbing fixtures.
Can PVC pipe be exposed to the sun?
PVC does not readily degrade when exposed to sunlight (ultraviolet radiation) due to natural UV inhibitors present in the material. Short-term exposure to sunlight, such as during construction, is typically not a problem for PVC pipe. PVC piping may be used in outodoor applications when the piping system is painted with a light-colored water based acrylic or latex paint that is chemically compatible with PVC. When painted, the effects of UV exposure are significantly reduced.