Selection and application of filter

Principles and requirements of filter selection

The filter is a small equipment for removing a small amount of solid particles in the liquid, which can protect the normal operation of the equipment. When the fluid enters the filter cartridge with a certain specification of filter screen, its impurities are blocked, and the clean filtrate is discharged from the filter outlet. When it needs to be cleaned, just take out the detachable filter cartridge and reload it after treatment.

1. Inlet and outlet diameter of filter:

In principle, the inlet and outlet diameter of the filter shall not be less than the inlet diameter of the matching pump, which is generally consistent with the diameter of the inlet pipeline.

2. Nominal pressure selection:

Determine the pressure level of the filter according to the maximum pressure that may appear in the filter pipeline.

3. Selection of hole number:

The selection of the number of filter holes mainly considers the particle size of impurities to be intercepted, which is determined according to the process requirements of the medium process. The particle size that can be intercepted by various specifications of wire mesh can be found in the following table "filter screen specifications".

4. Filter material:

The material of the filter is generally the same as that of the connected process pipeline. For different service conditions, cast iron, carbon steel, low alloy steel or stainless steel filters can be considered.

5. Calculation of filter resistance loss

The pressure loss of water filter is 0.52 ~ 1.2kpa under the general calculated rated flow rate.

Application of filter

1. Stainless steel filter

Stainless steel filters are widely used in pipelines of steam, air, water, oil and other media; Protect various equipment, water pumps, valves, etc. of pipeline system; Prevent the blockage and damage caused by rust, welding slag and other impurities in the pipeline. Stainless steel filter has the advantages of strong pollution resistance, convenient sewage discharge, large circulation area, small pressure loss, simple structure, small volume and light weight. The filter screen is made of stainless steel with strong corrosion resistance and long service life.

2. Y-type filter

Y-type filter is an indispensable filtering device for the pipeline system conveying medium. Y-type filter is usually installed at the inlet end of pressure reducing valve, pressure relief valve, constant water level valve or other equipment to remove impurities in the medium and protect the normal use of valves and equipment. Y-type filter has the characteristics of advanced structure, low resistance and convenient sewage discharge.

3. Y-type pull rod telescopic filter

The Y-type pull rod telescopic filter adopts a new design, which combines the Y-type filter with the expansion joint. It has the advantages of simple structure and convenient use, and solves the defects of inconvenient installation on the fixed pipeline caused by the different length of flanges of various standard products. The pull rod telescopic filter is mainly used for water supply and drainage piping in high-rise buildings, multi-storey buildings or factories, and is usually installed at the inlet end of pressure reducing valve, pressure relief valve, constant water level valve or other main equipment, After the pull rod telescopic filter is installed, it is convenient to cut off the pipeline sundries or install and disassemble to ensure the normal use of valves or equipment.

4. Basket filter

The basket filter removes small equipment containing a small amount of solids in the liquid, which can protect the normal operation of compressors, pumps, other equipment and instruments; It is also a small equipment to improve product purity and purify gas. Therefore, basket filters are widely used in petroleum, chemical industry, chemical fiber, medicine, food and other industries. Basket filter is composed of shell, blowdown cover, filter element, filter screen, bolt, etc.

5. T-type filter

T-type filter is widely used in pipelines of steam, air, water, oil and other media to protect various equipment on the pipeline system, such as water pumps and valves, from blockage and damage to the pipeline caused by rust, welding slag and other sundries in the pipeline. The T-type filter produced by Shanghai rimei Valve Manufacturing Co., Ltd. has the characteristics of strong anti pollution performance, convenient sewage discharge, large circulation area, small pressure loss, simple structure and small volume; The filter screen of T-type filter is made of stainless steel, with strong corrosion resistance and long service life; T-type filter is also divided into direct flow type and baffle type. The density of filter screen is 10-120 mesh, and the temperature is 0 ~ 450 ℃, which can be selected according to the needs of users.