A silo bolt is a specific type of fastener designed for use in the construction and maintenance of storage bins or silos. Here is a detailed introduction:
Size: Usually available in sizes ranging from M5 - M16 or 3/16" - 5/8". Different lengths are suitable for different applications. To select the correct length, measure the thickness of all the pieces that will make up the joint. For example, for a 4.0 mm joint (2.0 mm sheet + 2.0 mm sheet), a 1" bolt is often used.
Grade: Commonly comes in grades 8.8, 10.9, Gr. 5, and Gr. 8. Higher - grade bolts have better mechanical properties and can withstand greater forces.
Materials: Usually made of carbon steel, alloy steel, MS (mild steel), copper, brass, or stainless steel (such as SS304, SS302, and SS316). Stainless - steel silo bolts are highly resistant to corrosion, making them suitable for use in harsh environments.
Finish: Options include white zinc - plated, yellow zinc - plated, auto - black - plated, chrome - plated, etc.. The finish helps protect the bolt from rust and wear. Some silo bolts also have special features like ribbed necks. The ribs under the head can dig into the surface of soft metal and plastic to prevent the bolt from turning when the nut is tightened.
Installation: The head of the bolt is always inside the tank or silo, with the nut and washer outside. Before the bolt is pushed through, a blob of tank - grade mastic (usually Sikaflex TS + ) is applied over the hole. This acts as a cushion between the bolt head and the sheet and seals the underside of the bolt head to the inner surface of the tank, protecting the bolt from corrosion. After the bolt is inserted, the erector on the outside places the washers on the protruding bolt and then puts the nut on, initially giving it about half a turn. Finally, the bolts are tightened with a nut runner to a specific torque. Where the sheet overlap is covered by a base or top angle, the nut next to this joint is only tightened to half the normal torque, and a tapered insert is usually fitted.
Use Precautions: When tightening the bolts, it is necessary to follow a specific order to ensure that the joint is even and the silo sheet is not stressed, which could damage the coating and reduce the life of the silo or tank.
Inspection: All silos and slurry stores should be inspected regularly, preferably every five years. The most common problem with silo bolts is the degradation of the plastic cap due to UV light, which frequently occurs in slurry tanks, usually affecting the heads of bolts in the top rings only.
Replacement: When a silo or tank is rebuilt, all bolts, nuts, and washers should be replaced as a matter of course. If individual bolts are found to be damaged or corroded during inspection, they should be replaced in a timely manner. It should be noted that when entering a slurry store to replace bolts, it is essential to test for poisonous gases first and carry a gas alarm at all times.
HAIYAN BOLT CO.,LTD. produce both carbon steel and stainless Silo bolt.
