Epsilon Range Design Specification

Transcription

1 Epsilon Range Design Specification 1. General This specification outlines the design and materials of construction requirements for pump selections utilising the Epsilon range of pumps or similar for general industry and environmental applications. The specification is general in its application, covering the standard range of design options and materials of construction. It does not cover special designs or special material variations. The specification covers all models within the range. 2. Pump s 2.1 Suction s (Drive End) It shall be possible to rotate the suction casing through 270 degrees, in 90 degree increments, to accommodate three possible port orientations. On request or where appropriate, suction casings shall be capable of being supplied with an access port near to the rotor head to allow for clearance of blockages if required. The port cover must be bolted in place In the interests of safety no quick release fasteners are permitted. s shall be supplied with suitable threaded connections to allow for priming and draining, where required, or for the connection of pressure monitoring equipment. Materials of construction for cast iron pumps castings shall be to specification ENGJLHB195 or equivalent. Alternatively fabricated carbon steel to specification BS EN Grade S275, or equivalent may be used. For stainless steel pumps castings shall be to specification, grade 316C16F or equivalent. Alternatively, fabrications are acceptable using stainless steel conforming to BS EN 10088, grade X2CrNiMo17122 or equivalent. 2.2 Discharge (nondrive end) s shall be supplied with suitable threaded connections to allow for priming and draining, where required, or for the connection of pressure monitoring equipment. Materials of construction for cast iron pumps shall be to specification BS EN 1561, grade ENGJL HB195 or BS EN 1563, grade ENGJS 400/18 or 420/12 or equivalent. Cast steel to BS3100, Grade A1 WCB is an acceptable alternative for high pressure applications where cast iron is not suitable.

2 For stainless steel pumps castings shall be to specification, grade 316C16F or equivalent. Alternatively, fabrications are acceptable using stainless steel conforming to BS EN 10088, grade X2CrNiMo17122 or equivalent. Alternatively, fabrications are acceptable using stainless steel conforming to BS EN 10088, grade X2CrNiMo17122 or equivalent. 3. Pumping element Pumping element design shall be based on the traditional single lobe rotor concept. This requires the rotor to be circular in cross section. The use of multilobe designs (such as 2/3, 2 in 3, Trilobe etc) are not permitted due to the relatively poor wear, solids handling and suction performance of such designs when used in a pump design of this type. Such rotors can be identified by their elliptical shape in cross section. 3.1 Rotor For abrasive applications, the rotor shall be manufactured in one piece from an alloy steel conforming to BS970, grade 708M40T/709M40T (ASTM A 322, grade 4140/4145) or equivalent. The rotor surface should be coated with hard chrome plate to a nominal thickness of 0.25mm (.010 ) at the scroll peaks (major diameter). The surface should be polished to a minimum of Ra 1.6 μm (63 μin) to maximise stator wear life. For applications requiring stainless steel, the rotor shall be manufactured, in one piece, from 316 stainless steel conforming to BS EN 10088, grade X2CrNiMo17122 or equivalent. If a wear resistant coating is required, the rotor surface shall be coated with hard chrome plate and the surface polished to a minimum of Ra 1.6 μm (63 μin) to maximise stator wear life. 3.2 Stator The stator shall be a one piece construction, utilising vulcanised rubber, chemically bonded into a carbon steel tube. The rubber grade should be selected to be chemically compatible with the pumped product. The stator assembly method should be by spigot location into the pump casings, clamped in place by the use of high tensile steel tie rods. Stators that are threaded on the end and require screwing into casings are not permitted due the contact of the pumped product with the stator rubber/tube bond interface and subsequent affect on integrity over time.

3 4. Pump Drive Train 4.1 Drive shaft This is to be of a plugin design for direct connection to a geared motor or separate bearing housing as required. Connection should be by means of a single pin through the shaft. Alternatively a combined pump body and bearing housing with a onepiece drive shaft may be used on bare shaft pumps The shaft shall be manufactured from stainless steel conforming to BS EN grade X12Cr13 or X2CrNi189 or equivalent. Where 316 stainless steel is required, the shaft shall be made from material conforming to BS EN 10088, grade X2CrNiMo17122 or equivalent. Where a packed gland is specified, the area under the packing shall be coated with hard chrome plate to a minimum thickness of 0.13mm (.005 ). Hard chrome plate must not be used on shafts where mechanical seals are to be fitted. 4.2 Drive Connection The drive connection between the drive shaft and the rotor shall be of a flexible shaft design such as the Mono Flexishaft. Joints with wearing parts, such pin or gear joints shall not be permitted. The flexible shaft shall be manufactured in one piece from martensitic stainless steel to BS EN grade X17CrNi162 or equivalent and shall be coated with Halar to a minimum thickness of 0.8mm (0.032 ). Where a shorter flexible shaft is required, say due to space constraints, it shall be manufactured from titanium alloy to BS 2TA11:1974 or BS 2TA28 or equivalent. Titanium flexible shafts shall be coated with Halar to a minimum thickness of 0.8mm (0.032 ). Connection of the flexible shaft to the drive shaft and rotor shall be either by pinned, taper, bolted or clamped joint.

4 5. Gland seal Unless otherwise specified or dictated by duty conditions, the gland seal shall consist of a single internally mounted bidirectional mechanical seal. Metallic parts should be manufactured in 316 stainless steel. Seal design should conform to the requirements of DIN Face materials should be Silicon Carbide. The use of carbon on steel based face materials is not permitted due to relatively poor wear life. Packed glands are nonpreferred and only specified for duties where the use of a mechanical seal is not recommended. 6. Pump primary drive This should be by direct connection of the pump drive shaft utilising a positive location cross pin drive to a flanged mounted geared motor, rated at duty conditions to have a bearing life L10 (B10) of hours minimum and a load service factor of 1.0 minimum. On larger models where direct coupling is not possible, or where specified by the customer, the drive may be long coupled to the pump via a bearing housing. The bearings should be rated to give a minimum L10 (B10) bearing life of hours at the duty conditions. Drives should have a minimum service factor of 1.0

5 7. Material Specifications Item Material Description European Specification Nearest Equivalent UK Specification Nearest Equivalent US Specification Pump Body Suction Suction Extension (Where fitted) Discharge Rotor Drive Shaft Flexible Shaft Baseplate (if supplied) Fabricated Stainless Carbon Stainless Alternative Alternative Cast Fabricated Stainless Alloy Stainless Stainless Standard Spec n Stainless High Spec n Stainless Titanium Mild BS EN X2CrNiMo17122 BS EN Grade S275 BS EN X2CrNiMo17122 ENGJLHB195 BS EN 1563 Grade ENGJS 400/18 BS EN 1563 Grade ENGJS 420/12 BS EN X2CrNiMo17122 BS EN Grade 42CrMo4 BS EN X2CrNiMo17122 BS EN X2CrNi 189 or X12CR13 BS EN X2CrNiMo17122 BS EN X17CrNi162 BS EN Grade S275 Grade 220 or 260 Grade 40B Grade 316 C16F Grade CF8M BS 970 Grade Grade BS 1449 ASTM A570 Grade HR 43/20 Grade 40 BS 970 Grade Grade BS 2789 Grade 400/18 ASTM A536 Grade 60 BS 2789 Grade /12 Grade ASTM A216 Grade A1 WCB WCA Grade ASTM A M40T or 709M40T Grade 4140 or 4145 Grade BS970 Grade 304 S11 or 410 S S29 BS 2TA11 or BS 2TA28 BS 1449 Grade HR 34/20 Grade 304L or 403 Grade Grade 431 ASTM B34894a Grade 5 ASTM A570 Grade 40 Note: Due to either commercial or technical reasons it may be necessary to change or offer alternate materials of construction to those indicated above, however Mono Pumps Ltd will only offer materials of construction that we feel will be suitable for their intended duties. Issue 01 January 2008