GB/T 36386-2018Specification of hygienic housing for microfiltration membrane elements (English PDF)

3.1 Terms and definitions

The following terms and definitions apply to this document.

3.1.1 Hygienic filter housing

A container-like housing for mounting filter cartridges that meets clean and bio-safe requirements.

Note: mainly by cylinder, head, barrel connection, filter seat, tie rod, pressure plate, filter medium inlet, filter medium outlet, pressure gauge interface, exhaust port, sewage Port, sampling port, temperature sensor interface, fasteners, legs and so on.

3.1.2 Host material

Stainless steel material in direct contact with the filter media.

3.1.3 Filler metal

In the welding process, participate in the general term for the formation of weld metal welding materials.

Note: such as welding rod, welding wire, filler wire, flux, preset filler metal, metal powder, fuser, etc. are all filler metals.

3.1.4 Retention volume

The volume of liquid remaining in the filter housing after the drain opening is opened.

3.1.5 Dead end

An area that can retain fluid, cannot be drained, or cannot be cleaned.

3.1.6 Hygienic gasket

Flat annular gasket for sanitary joints.

3.1.7 O-ring

An annular seal with a circular cross section.

3.1.8 Nondestructive testing

Under the premise of not damaging the object to be inspected, physical or chemical means, with the aid of the corresponding equipment and equipment, in accordance with the prescribed technology To test and test the structure, properties or state of the interior and surface of the object, and analyze and evaluate the results. [NB/T 47013.1-2015, Definition 3.1]

3.1.9 Incomplete penetration

The root of the joint is not completely penetrated during welding. For butt welds, it also refers to the phenomenon that the welding depth does not meet the design requirements. [NB/T 47013.1-2015, Definition 3.2]

3.1.10 Lack of fusion

The unbonded portion between the weld metal and the base metal or weld metal weld layers.

Note: Unfused may be in one of the following forms.

a) the side walls are not fused;

b) the layers are not fused;

c) The roots are not fused.

3.1.11 Slag

Slag remaining in the weld metal.

Note: Depending on the formation, these slag inclusions may be.

a) linear;

b) isolated;

c) Clustered.

3.1.12 Burn through

During the welding process, the molten metal flows out of the perforations formed from the back of the groove. [NB/T 47013.1-2015, Definition 3.5]

3.1.13 Overlap

During the welding process, the molten metal flows to the metal tumor formed on the unmelted base metal or weld. [NB/T 47013.1-2015, definition 3.6]

3.1.14 Undercut

An irregular gap in the base metal (or the previous deposited metal) due to welding at the weld toe. [NB/T 47013.1-2015, Definition 3.7]

3.1.15 Porosity

When the molten metal solidifies, the gas therein does not escape and the formed void remains. [NB/T 47013.1-2015, definition 3.8]

3.1.16 Crack

A gap created by a new interface formed by the destruction of the bond of metal atoms. [NB/T 47013.1-2015, definition 3.9]

3.1.17 Corrosion

Physical-chemical interactions between metals and the environment (usually electrochemical properties), which result in changes in the properties of the metal and often The function of the technical system that leads to metals, the environment or by which they are part is compromised. [NB/T 47013.1-2015, Definition 3.10]

3.1.18 Shrinkage

Holes in the casting during the solidification process due to poor shrinkage. Very irregular shape, rough wall and dendritic crystals, often appearing The part where the casting is finally solidified. [NB/T 47013.1-2015, definition 3.11]

3.1.19 Loose

The inside of the casting or forging is defective in the distribution of fine pores. [NB/T 47013.1-2015, definition 3.12]

3.1.20 Inclusion

Defects formed by mixing non-metallic slag or refractory materials in castings or forgings. [NB/T 47013.1-2015, definition 3.13]

3.2 Abbreviations

The following abbreviations apply to this document.

GMAW. gas metal arc welding (gas metal arc welding)

GTAW. Tungsten inert gas shielded welding (gas tungsten arc welding)

PAW. plasma welding (plasma arc welding)

PMI. Material Reliability Identification (positive material identification)

SAW. submerged arc welding (submerged arc welding)

SMAW. automatic protection metal arc welding (shielded metal arc welding)

4.1 Compatibility with filter media

The main body material and filler metal of the outer casing should be able to withstand the corrosion of the filter medium at the use temperature, reach the design life, seal The material should maintain a reliable seal in the filter media and the polymer coating should not be easily peeled off.

4.2 Biosafety

The extractor or leachate released from the main body material, filler metal, sealing material and polymer coating of the outer casing to the filter medium shall not be visible. The biosafety of the filter media.

4.3 Steam sterilizability

All parts of the casing and sealing material should be able to withstand saturated steam not less than 130 °C (gauge pressure not less than 0.165 MPa) online Sterilize.

4.4 Washability

All parts of the enclosure should be clean.

4.5 Liquidity

The casing must not have dead spots due to gaps or dents, and the filter media should be able to flow sufficiently in the casing.

4.6 Exhaustion

The sewage outlet should be placed at the lowest point of the outer casing. After opening the sewage outlet valve, the filter medium in the outer casing should be able to be discharged by its own gravity.

Out, reduce the retention volume, the surface residual liquid height of any part should be no more than 2mm.

4.7 Surface finish

All surfaces of the parts in direct contact with the filter media should be finely polished or coated, resulting from sealing, nozzles, surface treatment, etc.

Defects such as pits and gaps shall comply with the provisions of this standard; and threads shall be avoided. When threaded fasteners are required, the threads shall be used. The ring is isolated.

4.8 Surface cleanliness

The inner and outer surfaces of the outer casing shall be free of impurities such as welding slag, polishing paste, oil stains, scale and dust.

4.9 Sealing

The sealing surfaces of the outer casing, including the cylinder, the filter interface, the nozzle, etc., should have good sealing.

4.10 Traceability

The manufacturer of the enclosure should have strict quality control procedures in place to ensure that the source of the material and its processing can be traced back to ensure the process The material will not be confused.

5.1 Body material and filler metal

5.1.1 Selection of main materials

The main body material of the outer casing should be austenitic stainless steel or austenitic-ferritic (duplex) stainless steel in Table 1, the main body materials of each part Types and applicable standards should be in accordance with Table 2.

5.1.2 Selection of filler metal

5.1.2.1 Grades of metal filling

The filler metal grades corresponding to different host materials shall comply with the requirements of Table 3.

5.1.2.2 Ferrite content of filler metal

The ferrite content in the filler metal can be determined by both the supplier and the buyer, and sealed according to the provisions of GB/T 1954. Ferrite content Increase or decrease should not affect the corrosion resistance of the outer casing.

5.1.3 Corrosion resistance of bulk materials and filler metals

The corrosion resistance of the main body material and filler metal of the outer casing shall meet the following requirements.

a) The body material and filler metal of the enclosure shall be resistant to pitting, crevice corrosion, stress corrosion and intergranular corrosion of the filter media, For the corrosion resistance test of stainless steel, see A.1 in Appendix A;

b) Corrosion of the filter media to the material shall not affect the sealability of the filter element interface, the cleanability of the outer casing and the pressure resistance, due to stainless steel The release of substances caused by corrosion shall not affect the quality of the filter media;

c) The general design life of the outer casing shall be not less than 10 years, unless the supply and demand sides confirm the reduction of the design service life;

d) When the corrosion parameters of the filter medium to the material cannot be confirmed during design, the corrosion rate shall be measured according to the method specified in JB/T 7901;

Or choose stainless steel with high pitting corrosion equivalent (NPRE) value. For the calculation of NPRE, see A.2.

5.1.4 Inspection of chemical composition of host materials and filler metals

The manufacturer of the enclosure shall provide at least one of the following chemical composition test documents for the host material and filler metal.

a) proof of source of material containing chemical composition analysis;

b) re-examine the chemical composition of the material in accordance with the method specified in GB/T 11170;

c) Material Reliability Identification (PMI), see A.3.

5.2 Polymer materials

5.2.1 Selection of polymer materials

The outer casing sealing material should be coated with fluoropolymer with thermosetting rubber or thermosetting rubber without asbestos. The commonly used materials are shown in Table 4. outer The shell coating material should be a thermoplastic polymer without asbestos composition. The commonly used materials are shown in Table 5.

5.2.2 Biosafety of polymeric materials

The polymer material shall have no acute systemic toxicity according to GB/T 16886.11, and the extraction conditions are as follows. mass concentration is 9g/L The sodium chloride injection and the freshly refined vegetable oil were leached at 70 °C ± 2 °C for 24 h ± 2 h, and the ratio of the surface area of the sample to the extract was 6 cm²/mL ± 0.6 cm²/mL.

5.2.3 Quality documentation for polymer materials

At least the following quality documents should be provided for all polymer materials.

a) raw material manufacturer, brand, batch number;

b) additive components;

c) finished product number, batch number;

d) Date of manufacture.

6.1 Design parameters

Both the supplier and the buyer should confirm the following design parameters when ordering.

a) the enclosure category;

b) filter media;

c) design pressure or maximum allowable working pressure (if necessary);

d) design temperature;

e) the main material;

f) component materials that are not in direct contact with the filter media;

g) sealing material;

h) surface treatment requirements;

i) filter specifications (including filter diameter, length and interface) and quantity;

j) take over the standard, size and purpose;

k) pipe joint standards and specifications;

l) Other information that needs to be confirmed.

6.2 Shell category marking

The category mark of the outer casing is composed of the filter medium import and export arrangement code, the filter seat setting mode code and the filter quantity code.

The meaning of the code is shown in Table 6. See Appendix B for a schematic of the different types of enclosures.

6.3 Seal design

6.3.1 Sealing method

The cylinder flange or pipe joint of the outer casing shall be of sanitary seal, as shown in Figures 1a) and b); or O-ring seal, as shown in Figure 1c)

An ellipsoidal gasket or O-ring seal may be used between the valve body and the valve seat of the exhaust and drain valve.

6.3.2 Hygienic seal design requirements

Hygienic gasket seal design should meet the following requirements.

a) There is no gap between the gasket and the interface card slot;

b) there is no slip when the gasket is pressed and used normally;

c) The protrusion or depression of the gasket relative to the joint after pressing shall be no more than 0.6 mm, see Figure 2.

6.3.3 O-ring seal design requirements

O-ring seal design should meet the following requirements.

a) O-ring should not slide easily in the interface groove;

b) After the O-ring is pressed, it should fill the slot as much as possible, and it should be able to fully fill the gap at the joint, as shown in Figure 3;

c) In order to ensure the reliability of the seal, when the space permits, the O-ring with a larger diameter should be used as much as possible;

d) O-rings shall not affect their physical and chemical properties after thermal expansion or chemical expansion;

e) After the O-ring is installed, it does not include the coefficient of thermal expansion and chemical expansion, and the tensile elongation shall not exceed 5%;

f) the outer diameter of the O-ring should be no larger than the outer diameter of the groove to prevent bending;

g) O-ring compression should normally be maintained at 10% to 25%, and the shrinkage rate can reach 10% due to changes in materials and pressure. 30%, but not more than 30%;

h) The O-ring should be as close as possible to the fluid side;

i) O-rings conforming to GB/T 3452.1-2005 or ISO 3601-1:2012 standards should be selected, and the appearance should conform to GB/T 3452.2 Provisions.

6.3.4 Ellipsoid seal sealing design requirements

The ellipsoidal seal can be used for sealing between the valve body and the seat and should meet the following requirements.

a) When the gasket is pressed, the end surface should be able to fit seamlessly with the valve seat and the valve body, see Figure 4;

b) When the valve is opened, the gasket should not fall off easily;

c) The surface of the gasket should be free of cracks, pits, etc., which affect the sealing performance;

d) The resilience of the gasket shall ensure that the valve maintains a good seal after at least 1000 opening and closing.

6.4 Component design

6.4.1 Housing component composition

The components of the outer casing are shown in Table 7, and the components are marked in Appendix B.

6.4.2 Cylinder

The cylinder should be cylindrical, and the design of the internal pressure cylinder should meet the requirements of Chapter 3 of GB/T 150.3-2011.

The calculation shall comply with the provisions of Chapter 4 of GB/T 150.3-2011.

6.4.3 Head

The head should adopt an elliptical head or a dish-shaped head. The design calculation of the elliptical head should meet the requirements of 5.3 of GB/T 150.3-2011.

The design calculation of the dish-shaped head should meet the requirements of 5.4 of GB/T 150.3-2011.

6.4.4 Cylinder connector

The cylinder shall be flanged with O-ring seals, and the O-ring seal design shall comply with the provisions of 6.3.3. The diameter of the cylinder is not more than 150mm

The outer casing can also be connected by a sanitary pipe joint.

6.4.5 Filter holder

6.4.5.1 General design requirements for filter cartridges

The filter holder should meet the following requirements.

a) The filter holder should be set horizontally to ensure that the filter element is installed vertically; […]