For getting proper pipe fittings to be used in pipes of various sizes, certain specifications are to be known. These specifications cover the following:
- Specifications of Materials
- Specifications of Size
- Cleaning and care tips of pipe fittings
- Pressure and Temperature Ratings
Specifications of Materials
Various materials having different standards are used to make various types of pipe fittings like elbows, adapters, tees, flanges, etc. Some popular fabricated materials and specifications for pipe fittings are as follows:
- Nickel and Nickel Alloys: ASTM B-366, ASME SB-366, Nickel 200 & 201 (WPN & WPNL), Inconel 600 (WPNCI), Incoloy 800 (WPNIC), Incoloy 825 (WPNICMC), Monel 400 (WPNC), Alloy 20 (WP 20 CB), Hastelloy, C-276, C-4, C-22 etc.
- Stainless Steel: ASTM A-403 and ASME SA-403, 304, 304L, 304H, 304N, 304LN, 316, 316N, 316LN, 309, 310, 317L, 321, 321H, 347 etc.
- Chrome-molybdenum: ASTM A-234 & ASME SA-234,WP-5, WP-11, WP-9, WP-91, WP-22 etc.
- Aluminum: ASTM B-361, 5083, 66061, 5086
- Titanium: ASTM B-363 & ASME SB-363, WPT7, WPT12, WPT2
- Fiberglass / Composite
- Iron (Gray / Cast/ Ductile)
- Polyethylene (PE)
- Polypropylene (PP)
- PVC (Polyvinyl Chloride)
Specifications of Size
To determine the usage of a pipe fitting, size is a very important criteria. Here, the main considerations are inside diameter and outside diameter where the inside diameter (ID) has the fitting size matched to the inside diameter of connecting line. The outside diameter (OD) has the fitting size matched to the outside diameter of connecting line. Besides these, sizes also refer to-
- English / Fractional sizes: Measurement done in inches
- Metric sizes: Units in mm/cm
Cleaning and care tips of pipe fittings:
In most of the pipe fitting systems, contamination is the leading cause of problems. This problem demands for careful installation and regular maintenance so that the fittings can prevent any blockages or system breakdown. Depending on the type of the pipe fitting, there are different cleaning methods.
For example, one of the caring tips for cleaning hose or tube assembly is that the hose and tube assemblies should be blown out with filtered shop air or flushed and then should be blown out with a solvent which is chemically compatible with the hose material. The ends of the hose / tube assembly should be capped or plugged till the time the assembly is installed.
Pressure and Temperature Ratings:
Temperature and Pressure are the two important factors determining the safe and effective working of any industrial pipe fitting. The range of temperature and pressure depends on the final application, the material being used etc. There are various standards that are laid down in reference to the temperature and pressure parameters. These are as follows:
- Standard Temperature and Pressure (STP): This is commonly used to define standard conditions for temperature and pressure. These are important for the measurements and documentation of chemical and physical processes.
- Normal Temperature and Pressure (NTP): This is defined as air at 20 degree C (293.15 K, 68 degree F) and 1 atm ( 101.325 kN/m2, 101.325 kPa, 14.7 psia, 0 psig, 29.92 in Hg, 760 torr). Density is at 1.204 kg/m3 (0.075 pounds per cubic foot).
- Standard Ambient Temperature and Pressure (SATP): This refers to temperature at 25 deg C (298.15 K) and pressure of 101 kPa.
- International Standard Atmosphere (ISA): Defined to 101.325 kPa, 15 deg C and 0% humidity.
A pipe fitting published working pressure is the maximum pressure that the pipe should see while in service. A fitting’s published burst pressure is the value at which a brand new piece of pipe will fail during one time pressure test.