Standard Interfaces For Automated Valve Assemblies

Transcription

1 Standard Interface For Automated Valve Aemblie Uer have much to gain from the introduction of tandard interface between Actuator and Valve, Actuator and Solenoid, and Actuator and feed back intrument. Automated Valve have to meet an infinite range of purpoe and environmental condition. Thi ha led to an equally large number of Valve automation component. The correct attachment of thee component, one to another, i eential for the efficient functioning of the valve aembly and it' protection againt damage in the field. Automated Valve aemblie are expenive with over 80% of the total cot (Fig. I) in the automation component. They are invariably intalled in large control cheme where reliability and accuracy i the keynote and the cot of a breakdown i high. Benefit Uing tandard interface lead to lower intallation cot, reduce piping and poible ite damage, eaier and quicker maintenance and component replacement. Retrofitting to meet change of circumtance i promoted a the uer i not "locked in" to a particular upplier. Correct alignment of drive to eliminate wear dead band or malfunction of the Actuator/Valve drive train i more readily achieved. Thee are obviou advantage but the tandard need to be applied with knowledge and care to obtain maximum benefit, to protect expenive intallation and obtain optimum life and efficiency. Hytork Valve Automation Center ue thee interface and encourage all uer to adopt them in their own interet.

2 ISO Interface between Valve and Actuator for Quarter-turn Movement ISO 5211 Flange Dimenion *UNC Thread are upplied on Hytork Actuator upplied to the USA Maximum torque tranmitte d Nm inch.lb. Flang e type "F" diamete r "A" quare preferre d ize "B" diamete r hole *UN C No. of "B" hole Locatio n diamete r "C" Loca - tion dept h "D" F M6 1/ F M6 1/ F M6 1/ F M8 5/ F M10 3/ F M12 1/ F M16 5/ F M20 3/ F M16 5/ F M20 3/ Thi tandard lit the attachment dimenion for the interface between the Actuator/Valve or the Actuator/lntermediate Bracket/Valve. Bracket are bolted to the Valve mounting face, thu avoiding the need for keyway or dowel, a torque tranmiion i catered for by the compreion force between the two component part. The attachment dimenion are lited againt a maximum allowable tranmitted torque value and are: The pitch diameter, number and ize of attachment crew. A location pigot for alignment. The Actuator driver and driven Valve tem/adaptor dimenion.

3 Indirect Mounting Hytork Valve automation experience how that the following condition make indirect mounting the preferred option for the majority of application. The tandard allow Actuator to be mounted directly on to Valve flange without any intermediate bracketry or adaptor. However there are a number of reaon why it i unlikely that thi method will be widely ued, particularly with regard to pneumatic Actuator. Actuator izing: There i a very wide range of output poible from any one ize of pneumatic Actuator. The torque requirement of a ingle valve ize can vary widely due to different eat material and the nature, quality, preure and temperature of the controlled medium. Pneumatic Quarter-turn Actuator are deigned to operate afely in the Double Acting mode at the maximum preure which i coonly 120 pi (8 bar). However a thi preure i eldom ued in practice, the preure normally choen for the attachment feature i the more coon line preure of 80 pi (5.5 bar) but can be a low a 30 pi (2 bar). Comparatively an 80 pi (5.5 bar) Double Acting mode Actuator will yield about even time the end of troke output of a imilar ize of Actuator ued in the Spring Return mode at 30 pi (2 bar). However the Actuator mut be deigned to meet the mot evere condition a the manufacturer ha no control over poible uage. Therefore, the interface on the Actuator will be related to the torque generated in the Double Acting mode at a tated maximum preure. (In the UK member of the Britih Valve and Actuator Manufacturer Aociation (BVAMA) mut certify Actuator according to the BVAMA Code of Practice No 001/1292 for the torque output under tated tet condition.) Gland adjutment: Some Valve have gland which require acce for adjutment. Maintenance and afety check: Many plant operator init on acce to examine Valve Stem Seal and Stem function at frequent interval and do not want them obcured. Figure 3 Valve line preure pi (bar) Valve torque inch lb Double Acting Actuator Hytork Model Number at variou preure pi (bar) Spring Return Actuator Hytork Model Number at variou preure pi (bar) (Nm) 40 (2.7) 60 (4) 80 (5.5) 40 (2.7) 60 (4) 80 (5.5) 50 (3.4) 900 (101) 425DAG 280DAG 185DAG 680S40 425S65 280S (6.8) 1200 (136) 425DAG 280DAG 280DAG 680S40 680S65 425S (13.6) 1600 (180) 680DAG 425DAG 280DAG 1125S40 680S65 425S (27.2) 2500 (282) 1125DAG 680DAG 425DAG 1370S S65 680S (41) 3400 (384) 1125DAG 1125DAG 680DAG 2585S S S80 Thi example how a typical 4" reduced bore cla 300 oft eated ball valve. The chart demontrate how the actuator ize can vary with a ingle valve ize. In the example there are even (7) different actuator model which ue four different "ISO" flange - F07, F10, F12, F16

4 ISO 5211 Valve flange for direct mounting are not univeral: Only a mall number of Ball and Plug Valve currently manufactured provide an ISO Actuator mounting flange and thi i unlikely to change in the hort or even the medium term. Butterfly Valve are perhap a little more coon with thi feature. Cro preuriation due to Valve Stem Seal failure: There are recorded cae of direct mounting where tem Seal failure allowed cro leak between the controlled medium and the Actuator The medium can be at high preure and will damage the Actuator in extreme cae or caue it to act againt the air preure or Spring. Remote mounting i often neceary: Pipe inulation for high or low temperature or hazardou controlled media often require remote acce to the automation component for maintenance purpoe. Valve tem are widely variable: There are many different ize and hape (Square, Double DEE, and Keyed) of Valve tem, ome for hitorical and ome for technical reaon. Valve manufacturer are reluctant to change their deign and ISO 5211 ha compromied in recogniing a number of alternative but at the ame time giving preferred ize and hape. It i anticipated and hoped that new Valve deign will follow thee ize but it i alo certain that divere tem will perit for many year to come. Thee reaon explain why, (and Fig. 3 demontrate in chart form), it i unlikely that direct mounting of Actuator to Valve will be widely ued and indirect mounting will continue to dominate. Low Quality Material Poor Quality / Cheap Intermediate Bracket and Adaptor are expenive in the long run. It i urpriing, but true, that ome uer will wate their money by paying high price for quality Valve and Actuator and then limit their life and efficiency by having cheap mounting Bracket and Adaptor made and fitted by inexperienced upplier. Thi can caue ide load, wear, back-lah, mialignment and even malfunction or failure in extreme cae. Hytork Valve Automation Center have WIDE experience in the deign, manufacture and fitting of indirect mounting component and hold tock of coonly ued item for quick delivery purpoe.

5 Eential Feature Eential feature for Mounting Bracket The Mounting Bracket mut be ufficiently rigid to tranmit the given torque without twiting or imparting ide load or eccentric caing force on the Actuator and Valve Stem Bearing. The whole automated aembly relie on correct alignment and adequate deign to perform it full function efficiently and conitently. The Actuator drive mut poition the valve correctly and imultaneouly ignal thi achievement via the witch box mounted on top of the Actuator. It follow that a much attention to detail i needed for mounting Bracket a i given to the election of the Valve and Actuator. Eential feature for Adaptor The Adaptor fit in the drive train and compenate for the gap, introduced by fitting the Bracket, between the Valve tem and the female Actuator drive. Fig. 3 how how the Actuator ize can vary coniderably within a ingle Valve ize and the Adaptor i ued to adapt the Actuator drive to the Valve tem. Mot Actuator drive are female quare but many Valve tem are flatted (Double DEE) or keyed a well a quare. The dimenion for thee alternative drive are given in the ISO 5211 tandard. Some Valve Stem have been made from high tenile material a the Valve torque requirement have been increaed. Thi avoid major deign change to the Valve body but they are often maller than the ISO 5211 preferred ize. If the driving component i of material with a lower bearing tre limit than the tem thi can lead to gradual wear, back-lah and poible failure. Care in the manufacture of Adaptor i alo needed to prevent eccentricity which can introduce ide load and caue wear and malfunction to the Valve or Actuator. Uer hould alo be ure that the Actuator izing matche the Valve requirement. Too little torque can lead to incorrect Valve operation, too much may hear the Valve tem if the valve jam for any reaon. The ucceful automation of Valve need knowledge and experience. Hytork Valve Automation Center bring thi pecialiation to the aid of uer who are aware of the potentially high cot of hut down time and the poibility of dangerou incident due to inadequate automation deign. (In the UK, The Britih Valve and Actuator Manufacturer Aociation (BVAMA) have iued a Code of Practice No BVAMA 002/0393 entitled valve Actuator Mounting Kit.) The NAMUR Solenoid Control Valve Interface

6 (Fig. 5). NAMUR i the acronym for the German Chemical Indutry Working Party that produced thi tandard. - Normen Arbeitgemeinchaft fur Ma Und Regeltechnik. Thi i a pecification for a tandard interface between pneumatic Actuator and Solenoid/directional control Valve. Thi ha been generally accepted by uer and manufacturer alike. It provide for attachment directly to a matching interface on the Actuator and for direct connection to the preure upply/exhaut port. By adopting thi tandard the uer reduce ignificantly the piping and bracketry involved in fitting directional control Valve. Thi ave cot and reduce the chance of pipework being damaged during ue. It give the uer the facility to change from one upplier to another or change the function to match a change of condition a all Solenoid ranging from intrinically afe to normal non-hazardou condition can be made uing the ame interface. The VDI/VDE 3845 Auxiliary Equipment Attachment Back To Top (Fig. 6). The German organiation Verein Deutcher Ingenieure and the Verband Deutcher Electrotechniker have propoed a pecification for the mounting and drive arrangement for top mounted auxiliary intrument uch a witch boxe and poitioner. Thi i a ueful pecification and i being ued by many Actuator and Valve automation equipment manufacturer including HYTORK Valve Automation Center

7 Benefit Of Standard Interface Standard Interface for Automated Valve Aemblie Benefit Hytork Cutomer. Hytork Actuator and Acceorie meet ALL the above tandard. Provide lower aembled cot due to fewer package component. Provide engineered, rugged attachment of all component. Provide greater flexibility in the election of component. Provide a more compact, rugged overall package. High Quality Hytork Mounting Bracket and Adaptor prevent damage to Valve and Actuator and ave expenive downtime.