Categories Starting with 'P' (Page #2)

PTFE or polytetrafluoroethylene is a synthetic fluoropolymer used to manufacture O-rings. PTFE (popular as Teflon®) is a highly chemically inert material that is resistant to almost all chemicals, such as bases, acids, oils, steams, among various others. In addition, it has excellent resistance to tearing and abrasion. This feature, coupled with a low coefficient of friction, has made PTFE O-rings an ideal choice for dynamic sealing applications, particularly in chemical environments. However, there are some limitations to using a PTFE O ring - their poor cold flow characteristics under lasting strain and their inability to compress as much as other elastomers, which makes them less effective. Despite this, exceptional resistance to most chemicals has made PTFE O-rings a perfect option for back-up rings.

Plastic machining is used for the fabrication of components made from a wide range of plastic materials such as PVC, nylon, acetal, ABS, polycarbonate, and acrylic. Common processes used to machine plastic components are turning, milling, and grinding. Heat transfer rate, softness, and brittleness of the plastic are some factors considered for effective machined plastics. The plastic machining process warrants the use of specialized cutting tools during fabrication to reduce heat build-up due to friction. The heat may distort or even melt the plastic, resulting in poor surface finishes or tear. Medical instruments, surgical implants, and food processing equipment are widely fabricated through the plastic machining process.

Using either plungers or pistons to compress and pump a fluid, a plunger pump is a type of reciprocating positive displacement pump often used in pumping systems. The plunger or piston is tightly fitted in a cylinder to create a cylindrical chamber, in which the working fluid is compressed before being discharged. The piston takes suction of the working liquid on the downward stroke and compresses the fluid on the return stroke, until the discharge valve or port is opened. At this point, the piston forces the water out the discharge with an increase in pressure. Available in various types, plunger pumps are classified based on the number of pistons or plungers used as well as their pumping arrangements. When classified based on the number of pistons, they are known as simplex, duplex, or triplex pumps; whereas based on their pumping arrangement, they are either single acting or double acting plunger pumps.

Prototype machining is an objective-oriented process executed by CNC machines to produce an object or part that would serve as a paradigm for a future final part. The process is conducted primarily to prove feasibility; however the prototypes obtained are not as effective or well-designed as the models produced later. This style of machining can perform operations ranging from an intricate 5-axis machining to fixing customer parts and generating simple-to-complex paradigms. In application, this machining approach offers engineers a platform to test the feasibility and effectiveness of their plans through the produced individual prototype parts.

PTFE gaskets are non-metallic sealing components that seal mating surfaces while remaining resistant to the medium that is being sealed, and exhibit high degree of tolerances toward the application pressure and temperature. They are fabricated from virgin PTFE or filled PTFE, a synthetic fluoropolymer that is inert to almost all chemicals, and exhibits low friction coefficient, fine thermal insulation, and processing and mechanical properties. Such properties make the gaskets of this type highly applicable in bearings, valve seats, non-lubricated compressors, as well as in applications involving corrosive chemicals, solvents and high temperatures.

A pressure transducer is a device which converts applied pressure into an electrical signal. A pressure transducer is primarily used to monitor the water levels.

Positive displacement pumps seal water in a chamber, and then force it out by reducing the volume of the chamber. Piston, diaphragm and rotary vane pumps are examples of positive displacement pumps. They are used for low volume and high lift.

Photo chemical machining is a machining methodology to create unstressed, high-precision parts or to etch parts. The machining mode exploits the image transfer technology to generate an exact, acid-resistant image of the object part on a flat metal piece. The work piece is etched into shape by chemical supplements that swallow the uncoated metal surrounding the work piece. PCM is also identified as photo fabrication, chem. milling, photo etching, photo chemical milling and chemical blanking. This machining is significant in the creation of thin and decorative elements.

Permanent mold casting is a casting methodology that uses a metal, predominantly iron, to originate the mold. This process is cheaper and effective to meet concerns in large-scale manufacturing since permanent molds are serviceable for more than one casting. Mold casting of this type may also use cores and molds of steel or any other metal. Castings produced through this approach can be reinforced to surpass the strength of either sand or die castings. Semi-permanent mold casting, which utilizes expendable cores made of sand or any other material, is employed when removal of permanent cores from the finished part is infeasible.

A pump system includes all the piping, including the equipment, starting at the inlet point and ending at the outlet point.