P

=P - Welding Glossary=


 * Partial Joint Penetration ** - Joint penetration, which is less than complete. See also complete joint penetration.


 * Pass ** - A single progression of a welding or surfacing operation along a joint, weld deposit, or substrate. The result of a pass is a weld bead, layer, or spray deposit.


 * Peel Test ** - A destructive method of inspection, which mechanically separates a lap joint by peeling.


 * Peening ** - The mechanical working of metals using impact blows.


 * Personal Protective Equipment**


 * PHOSGENE - ** Phosgene is formed by decomposition of chlorinated hydrocarbon solvents by ultraviolet radiation. It reacts with moisture in the lungs to produce hydrogen chloride, which in turn destroys lung tissue. For this reason, any use of chlorinated solvents should be well away from welding operations or any operation in which ultraviolet radiation or intense heat is generated.

**Phosphine** - Phosphine is colourless gas with a fish or garlic like odour. Contact with phosphine is generally through inhalation, skin and/or eye contact (liquid). Symptoms of toxic Phosphine exposure may include nausea, vomiting, abdominal pain, diarrhea; thirst; chest tightness, dyspnea (breathing difficulty); muscle pain, chills; stupor or syncope; pulmonary edema; liquid: frostbite
 * Plano Lens (eye protection) - ** A lens, Plano lens is a lens, which does not incorporate correction.


 * Plasma - ** Plasma is a gas that has been heated to an at least partially ionized condition, enabling it to conduct an electric current. Plasma is on of the four fundamental states of matter (the other being solid, liquid, and gas) Our Sun, and all the [|stars] are made of plasma.


 * Plasma Arc Cutting ** **(PAC) -** Plasma arc cutting uses, an inert gas (in some units, compressed air) is blown at high speed out of a nozzle; at the same time an electrical arc is formed through that gas from the nozzle to the surface being cut, turning some of that gas to plasma. The plasma is sufficiently hot to melt the metal being cut and moves sufficiently fast to blow molten metal away from the cut.

Powermax 45 Plasma Cutter - **Hypertherm Powermax 45 200-240V 1-PH Plasma Cutter w/ 20 ft. Hand Torch**


 * Plasma Arc Welding (PAW) - ** An arc welding process which produces coalescence of metals by heating them with a constricted arc between an electrode and the workpiece (transferred arc) or the electrode and the constricting nozzle (non transferred arc). Shielding is obtained from the hot, ionized gas issuing from the orifice, which may be supplemented by an auxiliary source of shielding gas. Shielding gas may be an inert gas or a mixture of gases. Pressure may or may not be used, and filler metal may or may not be supplied.


 * Plug Weld ** - A circular weld made through a hole in one member of a lap or T-joint fusing that member to the other. The walls of the hole may or may not be parallel and the hole may be partially or completely filled with weld metal. (A fillet welded hole or a spot weld should not be construed as conforming to this definition.)


 * Polarity ** - See Direct Current Electrode Negative, Direct Current Electrode Positive, Straight Polarity and Reverse Polarity. The polarity of a machine refers to direction of current flow. Polarity can only be obtained on a DC machine


 * Pocket Risk Assessment**


 * Porosity ** - Cavity type discontinuities formed by gas entrapment during solidification.


 * Positioned Weld ** - A weld made in a joint, which has been so placed as to facilitate making the weld.


 * Position Of Welding ** - See flat, horizontal, vertical, and overhead positions and horizontal rolled, vertical pipe welding positions.


 * Post Heating ** - The application of heat to an assembly after a welding, brazing, soldering,


 * Post-Weld Heat Treatment ** - Any heat treatment subsequent to welding.


 * Pounds Per Square Inch (psi) ** - A measurement equal to a mass or weight applied to one square inch of surface area.

**Power Efficiency** - How well an electrical machine uses the incoming electrical power.


 * Power Factor Correction ** - Normally used on single-phase, constant current power sources, to reduce the amount of primary amperage demanded from the power company while welding.


 * Preheating ** - The application of heat to the base metal immediately before welding, brazing, soldering, thermal spraying, or cutting.


 * Preheat Temperature ** - A specified temperature that the base metal must attain in the welding, brazing,soldering, thermal spraying, or cutting area immediately before these operations are performed.

Propagation of a Flame -

 * Primary Power ** - Often referred to as the input line voltage and amperage available to the welding machine from the shop's main power line. Often expressed in watts or kilowatts (KW), primary input power is AC and may be single-phase or three-phase.


 * Procedure ** - The detailed elements (with prescribed values or ranges of values) of a process or method used to produce a specific result.


 * Procedure Qualification ** - The demonstration that welds made by a specific procedure can meet prescribed standards.


 * Progressive Block Sequence ** - A block sequence during, which successive blocks are completed progressively along the joint, either from one end to the other or from the center of the joint toward either end.


 * Protective Atmosphere ** - A gas envelope surrounding the part to be brazed, welded or thermal sprayed, with the gas composition controlled with respect to chemical composition, dew point, pressure, flow rate, etc. Examples are inert gases, combusted fuel gases, hydrogen, and vacuum.


 * Pulse ** - A current of controlled duration through a welding circuit.


 * Pulsed TIG (TIG-P) ** - A modified [|TIG] process appropriate for welding thinner materials.


 * Pulsing ** - Sequencing and controlling the amount of current, the frequency, and the duration of the welding arc.


 * Pulse Time ** - The duration of a pulse.


 * Pulsed MIG (MIG-P) ** - A modified spray transfer process that produces no spatter because the wire does not touch the weld puddle. Applications best suited for pulsed MIG are those currently using the short circuit transfer method for welding steel, 14-gauge (1.8 mm) and up.


 * Pulsed Power Welding ** - Any arc welding method in which the power is cyclically programmed to pulse so that effective but short duration values of a parameter can be utilized. Such short duration values are significantly different from the average value of the parameter. Equivalent terms are Pulsed Voltage or Pulsed Current Welding: see also Pulsed Spray Welding.


 * Pulsed Spray Welding ** - An arc welding method in, which the current in pulsed to utilize the advantages of the spray mode of metal transfer at average currents equal to or less than the globular to spray transition current.


 * Push Angle ** - The travel angle when the electrode is pointing forward. See also forehand welding.


 * Note: this angle can be used to define the position of welding guns, welding torches, high energy beams, welding rods, thermal cutting andthermal spraying torches, and thermal spraying guns

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