Bolt type for flange
There are two types of bolts used to connect flanges: single-head bolts and double-head bolts. Their threads are generally triangular metric coarse threads. Let’s take a closer look at these two products.
Single-head bolts are also known as hexagon-head bolts. Single-head bolts can be divided into semi-refined and refined ones, and semi-refined single-head bolts are the most widely used in medium and low pressure process pipelines. The commonly used materials for manufacturing single-head bolts include Q235A, 35 # steel and 25Cr2MoVA. It is commonly used for flange connection with nominal pressure below 2.5MPa. The applicable temperature depends on the bolt material. For example, the applicable temperature of bolts made of 35 # steel can reach 350 ℃; The applicable temperature of bolts made of 25Cr2MoVA steel can reach 570 ℃.
Most of the stud bolts used on the process pipeline adopt the equal-length stud refined bolts. Suitable for flange connection with high temperature and pressure. The materials include 35 # steel, 30CrMoA, 35CrMoA, 25Cr2MoVA, 0Cr19Ni9, 0Cr15Ni25Ti2MoAlVB, 37SiMn2MoVA, etc. The nominal pressure range is 1.6~32.0MPa, and the applicable temperature can reach 700 ℃.
Haihao Group has worked in the pipeline field for more than 40 years and is committed to providing one-stop service for customers. In addition to the production of flanges, steel pipes, elbows, tees and other pipe fittings, Haihao can provide the bolts, nuts and other products used with these pipe fittings, which greatly avoids the problem of product specification mismatch encountered by customers at the construction site. If you need the relevant products of the pipeline, choose Haihao, and you can get all the products you need at one time.