EASISLIDE LOW FRICTION BEARINGS

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Cathleen Cook
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ESISLIDE LOW FRITION ERINGS 1 WHT SLIDE ERINGS DO When structures get hot, they expand and this expansion has to be accommodated within the design of the structure.

1 ESISLIDE LOW FRITION ERINGS 1 WHT SLIDE ERINGS DO When structures get hot, they expand and this expansion has to be accommodated within the design of the structure. For example, bridges and buildings expand and contract as a result of changes in ambient temperature and pipelines expand or contract when the temperature of the fluid they are transporting changes. Failure to allow such items to expand can produce in them unacceptably high stresses and may also overload the equipment or structure to which they are attached. n extremely effective way of accommodating such expansion is to allow one item to move in relation to another and this can easily be achieved by using slide bearings to separate the expanding item from the supporting structure. However, it is important that the bearing is designed so that the frictional force between the item and the structure is kept to a minimum, to prevent the development of high loads and stresses. WHY USE ESISLIDE ERINGS? They incorporate PTFE or other low friction materials. The bearings are designed to achieve optimum performance, by careful specification of the bearing pad dimensions to achieve the ideal compressive stress. apable of operating completely dry, they require no lubrication. ble to withstand a wide range of environmental conditions operating at temperatures from minus 200 o to plus 400 o and are resistant to a wide range of organic and inorganic chemicals. an tolerate some embedment of small particles in the bearing pad without causing failure. ompact design which means they often fit into areas unsuitable for other types of bearing. Designed for easy on-site installation. Long and maintenance free life. lready operating successfully in a wide range of installations worldwide. ESISLIDE LOW FRITION ERINGS Pipe Supports Group offers a comprehensive range of slide bearings suitable for many industrial applications. We supply bearings in a range of materials to standard designs and we also design and supply non-standard bearings to suit particular applications. PTFE/ ERINGS Polished (1) stainless steel upper face and PTFE lower face both attached to carbon steel backing plates. PTFE sliding on polished (1) stainless steel gives optimum low friction performance, with reduced frictional loadings permitting more efficient structural design. For bearing pressures above 1MPa, coefficient of friction values will typically be <0.05 for virgin PTFE and <0.07 for filled grades. oefficient of friction reduces with increasing bearing pressure. On PTFE/stainless steel bearings, the stainless steel surface is made larger than the PTFE by an amount exceeding the lateral movements. This means that the PTFE surface is always in full contact with the stainless steel, ensuring no increase in bearing pressure or damage to the PTFE surface caused by the edge of the harder stainless steel plate pressing into the PTFE. It is usual to install PTFE/stainless steel bearings with the larger stainless steel plate uppermost so that dust cannot settle on the larger plate, though design considerations may necessitate installation with the PTFE at the top. PTFE does tolerate some embedment of small particles without significant effect on performance

2 ESISLIDE LOW FRITION ERINGS PTFE/ ERINGS REOMMENDED MXIMUM ERING PRESSURE PTFE will suffer from creep under high loading, this effect increasing at higher temperatures. Pipe Support Group s maximum recommended bearing pressures are shown on the following graph. STNDRD ERINGS WITH ONDED PTFE ES07 ERING onded Virgin PTFE/Stainless Steel ES07 (1) POLISHED VIRGIN PTFE, ONDED Figure 1 For PTFE bearings where the PTFE is affixed to the backing plate solely by bonding, a maximum PTFE service temperature of 120 is recommended. Where the PTFE is contained in a machined recess in the backing plate, a maximum temperature of 250 is applicable. Note that if EasiSlide bearings are fitted below pipe shoes on insulated pipework, there will be a temperature drop through the shoe and insulation; the bearing will not be at the same temperature as the pipe. PTFE/ ERINGS STNDRD ERINGS For the standard designs, the bottom plate is square. The top plate may be square or rectangular, depending on required movement in the co-ordinate directions. For efficient selection of travel range, the relative positions of top and bottom plates can be offset on installation. acking plates are carbon steel as standard but can be supplied in stainless steel if requested. Travel Range 1 = +/- 12.5mm Movement Travel Range 2 = +/- 25mm Movement Travel Range 3 = +/- 37.5mm Movement earings can be supplied with different thickness if requested. are should be taken that the backing structure has adequate strength and rigidity. Loading at 25º (Sq.) (mm) ES07DS ERING onded Virgin PTFE/Stainless Steel with Dust Seal ES07DS ONDED PTFE DUST SEL Loading at 25º (Sq.) (mm)

3 ESISLIDE LOW FRITION ERINGS 1 ES08 ERING onded Glass-Filled PTFE/Stainless Steel ES08 STNDRD ERINGS WITH PTFE IN MHINED REESS ES10 ERING Virgin PTFE in Recessed acking Plate/Stainless Steel 2 GLSS-FILLED PTFE, ONDED Loading at 25º (Sq.) (mm) ES09 ERING onded ronze-filled PTFE/Stainless Steel ES10 VIRGIN PTFE, REESSED KING PLTE Loading at 25º (Sq.) (mm) (kg) (3) (4) Movement ES09 RONZE-FILLED PTFE, ONDED ES11 ERING Glass-Filled PTFE in Recessed acking Plate/Stainless Steel ES11 6 Loading at 25º (Sq.) (mm) GLSS-FILLED PTFE, REESSED KING PLTE Loading at 25º (Sq.) (mm) (kg) (3) (4) Movement

ESISLIDE LOW FRITION ERINGS ES12 ERING ronze-filled PTFE in Recessed acking Plate/Stainless Steel PTFE earings pplications and Non-Standard Designs ES12 RONZE-FILLED PTFE, REESSED KING PLTE Loading

4 ESISLIDE LOW FRITION ERINGS ES12 ERING ronze-filled PTFE in Recessed acking Plate/Stainless Steel PTFE earings pplications and Non-Standard Designs ES12 RONZE-FILLED PTFE, REESSED KING PLTE Loading at 25º (Sq.) (mm) (kg) (3) (4) Movement Non-Standard EasiSlide earings on ym Dyli HEP Station, Gwynedd, Wales. Use with Pipe shoes ES07 to ES12 Slide earings are compatible with pipe clamp bases Types P1-P4 Notes (1) Polished to a surface finish according EN class 2 (Equivalent to STM 480 No.2) (2) for use up to a maximum temperature of 120 (3) for use up to a maximum temperature of 250 (4) For temperatures greater than 25, reduce the maximum loading as per Figure 1 Typical Designation ES RNGE 1 X RNGE 3 Use with Load-earing Thermal Insulation THERML INSULTION MTERIL PTFE RON For high temperature application, when using PTFE bearings, it is necessary to use load bearing thermal insulation to reduce the temperature at the bearing face. This is an alternative to using high temperature slide bearings see next page. 190

ESISLIDE LOW FRITION ERINGS 1 Design for Large Movement We can supply non-standard designs of types ES07 to ES12 to allow for movements greater than Range 3 (+/-37.5mm).

5 ESISLIDE LOW FRITION ERINGS 1 Design for Large Movement We can supply non-standard designs of types ES07 to ES12 to allow for movements greater than Range 3 (+/-37.5mm). For pipework applications with very large horizontal movements, the standard design of PTFE/stainless steel bearing with the large upper plate may not be practical. Large lateral movement could cause the pipe shoe to twist around the pipe, or a twisting moment can be applied to the pipe which is also undesirable. In these circumstances, it may be preferable to install the bearing with the smaller PTFE-bearing plate at the top. PTFE on PTFE designs with overlapping strips of PTFE can also be considered. Note that an increased coefficient of friction will apply for PTFE-on-PTFE bearings and a lower bearing pressure should be used. HIGH TEMPERTURE SLIDE ERINGS STNDRD DESIGN ES13 is always in full contact. The bottom plate is square. The top plate may be square or rectangular, depending on required movement in the co-ordinate directions. For efficient selection of travel range, the relative positions of top and bottom plates can be offset on installation. acking plates are carbon steel as standard but can be supplied in stainless or alloy steel if requested. The standard ES13 slide bearing is designed for a maximum bearing face temperature of 400 (752 F). For conventional high temperature piping installations using pipe clamp bases types P1 to P4, the temperature drop through the clamp base should result in a bearing face temperature less than 400. For ES13 bearings, a coefficient of friction of approximately 0.15 should be expected. ES13 ERING Lower Plate with Graphite Pad/Polished (1) Stainless Steel Upper Plate ES13 POLISHED (1) 5 GRPHITE PD ES13 Lower Plate The ES13 standard high temperature bearing uses a Grade PSG03 graphite pad positively located on the lower plate. The upper plate comprises a polished (1) stainless steel plate welded to a backing plate. The size of the stainless steel plate is such that the graphite pad Max. Loading (Sq.) (mm) Size (at 400º) Movement kg mm mm Range 1 Range 2 Range Travel Range 1 = +/- 12.5mm Movement Travel Range 2 = +/- 25mm Movement Travel Range 3 = +/- 37.5mm Movement earings can be supplied with different thickness

6 ESISLIDE LOW FRITION ERINGS if requested. are should be taken that the backing structure has adequate strength and rigidity. Notes (1) Polished to a surface finish according EN class 2 (Equivalent to STM 480 No.2) Typical Designation ES RNGE 1 X RNGE 2 Use with Pipe shoes ES13 Slide earings are compatible with pipe clamp bases Types P1-P4 Design for Large Movement We can supply non-standard designs of type ES13 to allow for movements greater than Range 3 (+/-37.5mm). High Temperature Slide earings Non-Standard designs Pipe Supports Group design and supply high temperature slide bearings to customer requirements. vailable Materials include: Leaded ronze Lubricated Manganese ronze Graphite-lubricated ast Iron Lubricated ronze earing Pad 192

EASISLIDE LOW FRICTION BEARINGS

EASISLIDE LOW FRICTION BEARINGS 1 WHT SLIDE ERINGS DO When structures get hot, they expand and this expansion has to be accommodated within the design of the structure. For example, bridges and buildings expand and contract as a result