THE VELJAN ADVANTAGE - Hydraulic Valves

1 4 THE VELJAN ADVANTAGEMACHINE TOOLSMINING EQUIPMENTMOBILE MACHINERYPOWER PROJECTS EQUIPMENTMARINE EQUIPMENTSTABILISERS AND STEERING GEARSSTEEL MILL EQUIPMENTFORGE AND FOUNDRY EQUIPMENTPACKAGING MACHINERYPLASTIC MACHINERYV eljan s reputation as the designer and manufacturer of fluid power products of utmost reliablequality is an established fact for over 45years the back-up of up-to-date & state-of-the-art production facilities and a clear-cut focus ondesign engineering and product development, VELJAN effectively meets the demand for a verywide spectrum of applications, such as in :Besides Hydraulic and pneumatic cylinders for every conceivable application, VELJAN continues to engineer, manufacture and market a wide range of pneumatic achieve, maintain and provide a "single source system" facility, VELJAN s joint venture company manufactures high performance Hydraulic Pumps, Motors, Valves and Systems.

2 This has enabled VELJAN products and services to be reckoned as the benchmarks for this catalogue is intended as a brief guide to the selection of standard VELJAN HydraulicCylinders, VELJAN also offers customised equipment and the specials needed by its valued andsatisfied customers drawn from various sectors of the industry who have been regularly sourcingtheir requirements of these cylinders and other fluid power products from , with its proven track record, technical expertise, design and engineering capabilities inthe realm of high quality products and prompt services is confident of satisfying the exactingdemands of all its MACHINERYAMUSEMENT PARKS, offers various types of Hydraulic Cylinders for different pressure ratings and applications :Series-HTCompact tie-rod square type construction Hydraulic Cylinders rated for 160 bar with mountingdimensions conforming to ISO:6020 part 2 for 40 to 200 mm bore and ISO:6020 part 3 for 250and 320 mm bore welded round type construction of 160 bar medium series Hydraulic Cylinders withmounting dimensions conforming to ISO.

3 6020 - part 1, in bore sizes from 40 to 320 above HT and HR series cylinders are also suitable for use at working pressures upto 210 bardepending on the rod-end and mounting duty Hydraulic Cylinders rated for 250 bar pressure with mounting dimensions conforming toISO:6022, in bore sizes from 50 to Cylinders such as duplex, tandem, telescopic and other custom-designed types are regularlyproduced for various applications and pressures upto 500 bar and bores upto 800mm also manufactures a wide range of pneumatic cylinders rated for pressures upto 17 bar in boresizes ranging from 8 to 800 OF HYDRATYPES OF HYDRATYPES OF HYDRATYPES OF HYDRATYPES OF Hydraulic CYLINDERSULIC CYLINDERSULIC CYLINDERSULIC CYLINDERSULIC CYLINDERS66666 VVVVV eljan ofeljan ofeljan ofeljan ofeljan offers the following variety of seals to suit differs the following variety of seals to suit differs the following variety of seals to suit differs the following variety of seals to

4 Suit differs the following variety of seals to suit differferferferferent applications :ent applications :ent applications :ent applications :ent applications :SEALSSEALSSEALSSEALSSEALSPISTON SEALSELASTOMERICP iston seals with integralanti-extrusion Rings are fitted as a standard for160 bar seals withbearing rings conforming to ISO:6547dimensions and leak-tight under normaloperating conditions are optional. These aresuitable for speeds upto m/s and holdingloads in FRICTIONP iston Seals conforming toISO:7425-1 grooves employ an elastomerenergised PTFE ring and may be used for pistonspeed upto 5m/s. These are best suited wherevery low friction and an absence of stick-slipare needed, such as in Servo cylinders.

5 Thesepermit fine control of position, velocity andacceleration. However they are not suitable forload holding LOADED PTFEU-CUPS are suitablefor low as well as high temperatures. Formaximum dynamic sealing and to prevent turningor rolling, these seals are mechnically locked inplace and pressed against tubing IRON PISTON RINGS offer exceptionaldurability and are recommended for hightemperature application. Leakage inherent in thisdesign can result in slip, drift and varying feedrates and hence are not suitable for holdingloads in SEALSPOLYURETHANE internally lubricated Rod Sealswith hardness of 900 Shore A, are compatiblewith a broad range of temperature and have low compression set and excellentabrasion resistance.

6 They are designed to installeasily and function well in normal applicationsand are fitted as standard. Rod seals conformingto ISO 5597 are FRICTIONRod Seals to suit ISO:7425-2grooves, employ an elastomer energised PTFE ring and may be used for piston speeds upto5m/s. These are used in conjunction with similarPiston Seals indicated Seals are pressure-energized and wearcompensating, mechanically locked to preventblowout and will endure temperatures upto 2300F. They are compatible with most Hydraulic fluidsincluding fire-resistant WIPER protects the Rod Seal and bushfrom damage caused by dirt adhering to therod. The lip of the wiper removes the finest dirtfrom the piston PISTON SEALLOW FRICTION PISTON SEALPTFE U-CUPSCAST IRON PISTON RINGSPOLYURETHANE ROD SEALLOW FRICTION ROD SEALPTFE SEALROD WIPER88888 The following simple steps ensure that principalfactors are considered while selecting the cylinder :1.

7 First Establish :-Force (F) needed or weight to be moved-Stroke or distance to be Based on the available or selected systempressure P, calculate the cylinder areasrequired by using the formula F=P A for pushas well as pull Referring to the table below, choose theminimum bore & rod combination to providecalculated IN DIFFERENT BORE ROD COMBINATION4. Check the rod diameter for column strengthto resist push force in case of long strokecylinders (refer page 14), and also the speedratio between the return and forward strokes, Select the mounting style and the rod end/cap end accessories to fit your installationneeds. (refer pages 20 to 33)6.

8 Application considerations may require changesin your selection, and for assistance refer thefollowing Application Engineering TO SELECT A VELJAN CYLINDER :HOW TO SELECT A VELJAN CYLINDER :HOW TO SELECT A VELJAN CYLINDER :HOW TO SELECT A VELJAN CYLINDER :HOW TO SELECT A VELJAN CYLINDER :VARIATIONS FROM STANDARD1. Ports : BSP ports are standard. Other types like BSPT, NPT,`O ring seal ports, SAE flanged ports, manifold ports, etc.,can be optionally provided. Also refer Piston speed on Cushion Adjustments : Ball check and adjusting screws canbe interchanged without affecting port Mixed mounting for special or constrained Heavy chrome plated or stainless steel piston rods forcorrosive Longer rod extensions as Rod-end threads : Shouldered male threads in metric sizesare standard as listed in the basic cylinder dimensionstable.

9 These threads have turndown of approximately 50%of the Piston rod area. The screwing of the mating part isdone upto the shoulder, eliminating the need for variations are possible as follows :(i) Female threads of same size as indicated above - theseare useful for connecting mating parts such as rod-eyeshaving male threads.(ii) Unshouldered male threads. threads of full diameteras that of rod, useful when adjustment is needed, alongwith a locknut for locking the Check the followingAcceleration Check whether the calculatedandforce is sufficient to accelerate/Decelarationdecelerate the load within prescribeddistance. Check back-pressure riseduring cushioning is within speedCheck whether the standard port sizepermits sufficient oil flow to meetspeed strokeCheck whether a stop tube is neededhorizontalto prevent excess bearing loadmounting& column Check whether standard pistonloadingrod is strong enough in or low Below 00 C or above 800 C, springloaded PTFE/ Viton seals are to beopted.

10 For very high temperature,piston rings can be used if leakageis seals are compatible with mostbased fluidsfire-resistant and petroleum-basedfluids. Other seals are available forhigh water base and other Cap end Rod Head endmm area fordiaarea forpush cm2mm Pull cm2 40 50 63 80 ENGINEERING Bore Cap end Rod Headendmm area fordiaarea forPush cm2mm Pull cm2125 097084. 239059. 10160 162. 5890 137. 44110 106. 03200 250. 54110 219. 13140 160. 22250 140 336. 94160 289. 81180 236. 40320 180 549. 78200 490. 09220 424. 12temperature99999 ACCELERAACCELERAACCELERAACCELERAACCELERA TON & DECELERATON & DECELERATON & DECELERATON & DECELERATON & DECELERATION IN CYLINDERS :TION IN CYLINDERS :TION IN CYLINDERS :TION IN CYLINDERS :TION IN CYLINDERS :It is often necessary to determine the Force F required to accelerate or decelerate a given mass.