Engineering and technical requirements of metering pumps and related implementation guidelines

1. Scope The technical specifications of this project indicate the minimum requirements for metering pumps, their driving machines and auxiliary equipment for industrial installations. The engineering provisions of the metering pump performance, structural design, materials, drivers, tests, signs, packaging and procurement made provisions. 2. Standards, Codes and Regulations 2.1 Except for the technical provisions of this project, the performance of pump data shall also be observed. For example: GB9236 metering pump technical conditions; GB7783 metering pump test methods; and API675 metering pumps (Positive Displacement Pumps-Controlled Volume). 2.2 When the engineering specifications and specified standards conflict, the engineering provisions shall prevail. At the same time, the seller shall clarify the contradiction to the buyer in written form to remind the buyer to pay attention and solve it. 3. General 3.1 Unless otherwise specified, pumps, drives and their auxiliaries shall be suitable for outdoor start-up and continuous operation at the minimum and maximum ambient temperatures specified. Continuous operating cycle should not be less than 8000 hours. 3.2 The untested prototype can not be accepted, only the actual production of the pump can be accepted. The so-called production verification refers to the pump under similar operating conditions at least two years of safe operation experience. 3.3 Unless otherwise specified, the seller shall provide the entire pump set including pump, coupling, driver and all auxiliary equipment and ensure the quality of the entire pump set. 3.4 Unless otherwise specified, pumps, drives, couplings, shrouds and auxiliary equipment shall be mounted on the same base. 4. PERFORMANCE 4.1 The metering pump should be able to regulate the flow in both operating and non-operating conditions with an adjusted ratio of at least 10: 1 (ie 10% to 100% of the rated flow range) and 25% to 100% Pump stability should be within ± 1% accuracy, linearity and reproducibility accuracy should be within ± 3%. 4.2 Scale or adjust the hand wheel scale accuracy should be higher than ± 0.1% of the indicated accuracy. 4.3 The dosing pump should have a nominal flow rate at least equal to 110% of the maximum (operating) flow rate proposed by the user. 4.4 The motor rated power should be at least equal to K times the maximum shaft power of the metering pump (including the power loss of the gear box, coupling). K value is selected according to the following table. Maximum shaft power Pa (kW) Maximum shaft power Pa (kW) K Pa ≤ 3150% Pa ≤ 19125% 19Pa> 55110% 4.5 Effective NPSHa NPSHr and necessary NPSHr should be based on the same reference plane. When the difference between NPSHa and NPSHr is less than or equal to 0.6m, the NPSH should be carried out. 5. Structural Design 5.1 Pressure-Bearing Parts 5.1.1 The maximum permissible outlet pressure of the pump shall be at least equal to 110% of the rated outlet pressure of the pump. 5.1.2 All pressure parts (including the impact of the import pressure area) should be designed to allow the maximum outlet pressure pumping temperature, the allowable stress of the material taken: for domestic pump, should not be greater than HG20531-93 (cast iron, steel Container) maximum allowable stress value; Imported pumps, should not exceed ASMESectionVIII provisions of the maximum allowable stress value. 5.2 Interfaces 5.2.1 All interfaces are flanged unless otherwise specified on the data sheet. 5.2.2 Unless otherwise specified, domestic pump inlet and outlet connecting flange shall comply with the provisions of GB9112, import pump inlet and outlet connecting flange shall comply with the provisions of ANSIB16.1 and 16.5. Flanges with a diameter or thickness greater than the above are also permissible. 5.2.3 Import and export flanges should be taken at the same level of pressure flange. 5.3 Plunger Pumps 5.3.1 The stuffing box shall be fitted with a packing ring for flushing or lubricating the packing. 5.3.2 should ensure that the liquid end packing seal leakage liquid does not enter the power side. 5.4 diaphragm pump 5.4.1 single diaphragm pump diaphragm or double diaphragm pump first diaphragm should be limited agencies. 5.4.2 Double Diaphragm The two diaphragms of the pump should be filled with inert liquid (and the process medium on both sides of the diaphragm, the hydraulic oil should not be mixed), and a probe should be provided to alert the diaphragm when the diaphragm ruptures. 5.5 Bearing Bearings should be the standard form, shall not be made by the manufacturer's own non-standard bearings. 5.6 Buffers If specified on the datasheet, the import and export bouncers shall be provided by the seller and shall be of the type negotiated jointly by the buyer and the seller. 5.7 safety valve 5.7.1 diaphragm pump oil chamber safety valve should be able to automatically reset and adjust, repair, easy to replace, the set pressure should be at least 110% of the rated pressure of the metering pump. 5.7.2 If specified in the data sheet, the external relief valve for the plunger pump shall be provided by the seller. 5.8 Auxiliary piping 5.8.1 If piping systems such as lubrication, cooling and seal flushing are required, the seller shall provide and install it on the pump and / or base. 5.8.2 The plumbing, fittings, etc. of all piping systems shall be not less than 1/2 in. (13 mm) thick and shall not have a wall thickness of less than 1.6 mm (1/16 in.). 5.8.3 Pipe fittings of 1-1 / 4 (32mm), 3-1/2 (90mm), 7 (175mm), 9 (225mm) inches shall not be used unless otherwise specified. 6. Material 6.1 Material is to be filled by the purchaser on the pump datasheet. If the seller believes that other materials more appropriate, can submit a written report, but the adoption of the buyer's confirmation. 6.2 Unless otherwise specified, carbon steel, low alloy steel corrosion margin taken 3mm, high alloy steel 0mm. 6.3 Non-use of asbestos-containing fibers is prohibited. 6.4 Transporting organic solvents, non-use of rubber materials. 6.5 Conveying parts that are flammable, explosive or poisonous can not use cast iron. 6.6 In addition to austenitic stainless steel, when the media or the ambient temperature ≤-20 ℃, then sell X said embarrassing alluvial bald epeiror trout-type impact test. 7. Workshop Tests 7.1 Workshop Tests See Pump Data Sheet. 7.2 hydrostatic test pressure should be 1.5 times the maximum allowable working pressure, but not less than 0.14MPaG. Stability accuracy test is a must, the precision should be within ± 1%, and the repeatability accuracy test and linearity test are optional, the precision should be within ± 3%. 7.3 For the inspection or pilot project requiring buyer's presence, the seller shall notify the buyer at least 20 days after the test date is confirmed so that the buyer can participate in the project in time. 7.4 The result of the non-seeing test shall be recorded and sent to the buyer for approval. 8. Painting, marking, packaging 8.1 painting