Pipe Flanges

Joint of two flanges by bolts and nuts

Pipe flanges are collars that typically connect sections of pipe and are available in many sizes, shapes, and materials to suit different applications. Flange materials include carbon steel, alloy steel, stainless steel, cast iron, aluminum, brass, and PVC.  The diameter, length, and grade of A193 heavy hex bolts and studs used in flanged connections is determined by the type of steel or material used to make the pipe and flange as well as the amount of heat and/or pressure contained within the pipe and flange.  Flange bolts are often sold as kits with the quantities of bolts, nuts, washers, and gaskets matching the specific flange.  Common applications for piping and flanges include waterworks, petrochemical, and process industries. Common grades of A193 bolts and studs used in flange connections include B7, B8 (classes 1 and 2), B8M (classes 1 and 2), and B16.

Pressure Vessels

Natural Gas storage tanks in industrial plant.

Pressure vessels are spherical or cylindrical tanks designed to store or transport pressurized liquids or gasses. They are made from a variety of materials including carbon steel, stainless steel, and several exotic alloys.  Pressure vessels are engineered for safe operating temperatures and pressure, with a specific corrosion allowance and with specific safety factors. Some of the various industries utilizing pressure vessels include the US Government, oil and gas, aerospace, power generation, refining, chemical, food service, water treatment, and mining.  Uses include compressed gas storage, hot water storage, ammonia, chlorine, propane, and other liquefied gas storage, diving cylinders, pneumatic reservoirs, and may others. Common Grades of A193 bolts and studs used in pressure vessels are B7 and B16.


Old gas steel boilers established in old boiler-house

Boilers are vessels in which water or other fluid is heated. Boilers are typically manufactured from carbon or alloy steel, although historically they have been made from wrought iron. Boilers are often heated by wood, coal, oil, or natural gas.

Heat Exchangers

Heat exchanger in refinery plant

Heat exchangers are devices used to transfer heat between one or more fluids (liquid or gas) without mixing together. Industries using heat exchangers include petroleum refineries, natural gas processing, refrigeration, air conditioning, chemical plants, sewage treatment plants, and power stations, to name a few.


valvesA valve is a device for controlling the passage of fluid through a pipe. A193 bolt grade selection will be dependent upon the valve’s base material, the pressure class of the valve, and service conditions. For plain carbon steel valves, Grade B7 bolts are typically used. When high temperatures dictate the use of Cr/Mo valves, Grade B16 bolts are the norm. A193 Grades B8 and B8M are used with stainless steel valves.