Jim Mimlitz, NRI<\/p><\/div>In the rural and municipal water industries, valve control of pressure and flow has often been accomplished using diaphragm-type valves.\u00a0 These types of valves can be tuned to provide altitude control at water towers, pumping stations, and custody-transfer valve stations.\u00a0 The valves offer a no-slam open\/close actuation and can be tuned to sustain a desired back-pressure.\u00a0 However, these valves also present the owner with challenges.\u00a0 First, they tend to require a large amount of maintenance to both the diaphragm and the pilot tubes.\u00a0 Also, due to their reliance on narrow-gauge needle valves for tuning, they can become stuck in the open or closed position when those needle valves become clogged.<\/p>\n
![\"A](\"https:\/\/wireless-telemetry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_3122.jpg\")
<\/a>A Solenoid-Actuated Diaphragm Valve in a Pumping Station. This Valve Controls the Flow Into a GST (Ground Storage Tank).<\/p><\/div>\n
Because of these issues, many of our customers have challenged us to provide a more effective solution.\u00a0 Our approach, which was initially rolled out in 2002, is the digitally-controlled, motorized butterfly valve.\u00a0 Our initial solution consisted of a Jamesbury High-Performance Butterfly Valve driven by a Limitorque LY-series motorized actuator.\u00a0 In later applications, the newer Limitorque QX-series motorized actuator was used.<\/p>\n
<\/a>High-Performance Butterfly Valve. Designed for modulating and high-pressure-drop applications, this valve\u2019s disc seat contact axis is offset, which acts to virtually eliminate sliding contact between disc and seat.<\/p><\/div>\n
<\/p>\n
<\/a>Digitally-Controlled, Quarter-Turn High-Performance Butterfly Valves (Jamesbury) with Motorized Actuators (Limitorque QX).<\/p><\/div>\n
To\u00a0meet the same flow-control and back-pressure-sustaining goals, the Telemetry RTU controlled the position of the\u00a0valve by utilizing feedback control theory methods.\u00a0 As an example, such an installation could be used to open\/close a valve that fills a GST (ground storage tank).\u00a0 When the tank drops to a low level, the valve is opened to fill the tank.\u00a0 When the tank is full, the valve is closed to prevent the tank from overflowing.\u00a0 While filling the tank, the customer may wish to limit the flow (eg do not exceed 800 GPM), sustain backpressure (eg do not allow the backpressure to fall below 35 PSI), or both simultaneously.\u00a0 In laymen’s terms, if the flow begins to exceed the example setpoint 800 GPM, the Telemetry RTU slowly closes the valve until the flow rate drops back to 800\u00a0 GPM.\u00a0 Or, if the backpressure falls below 35 PSI, the Telemetry RTU slowly closes the valve until the backpressure climbs back to 35 PSI.\u00a0 Much like the cruise control adjusting the throttle on an automobile, the Telemetry RTU continuously monitors and adjusts the valve position in order to maintain a constant flow or backpressure.<\/p>\n
<\/p>\n
<\/a>V-Port Fully Closed<\/p><\/div>\n
<\/p>\n
<\/a>V-Port Partially Open<\/p><\/div>\n
<\/p>\n
<\/a>V-Port Fully Open<\/p><\/div>\n
The advantages of\u00a0this method over those based on\u00a0diaphragm valves are profound.\u00a0 First, the operational setpoints are fully integrated into the Telemetry system.\u00a0 Therefore, the Operator may adjust the settings remotely through the Telemetry software without having to be on-site.\u00a0 Secondly, the open\/close speed of the valve can be greatly reduced using a motorized actuator.\u00a0 For example, a valve can be tuned for a 20 minute time-to-open and a 20 minute time-to-close.\u00a0 A diaphragm valve could not be tuned for such a slow operation without soon experiencing a stuck operation.<\/p>\n
One particular Water Utility that takes full advantage of\u00a0throttled quarter-turn valve technology is Jersey County Rural Water (Jerseyville, IL).\u00a0 Jersey County Rural Water,\u00a0located\u00a0within Jersey, Macoupin, Madison, and Greene Counties, is one of the largest rural water districts in the State of Illinois; and it serves over 5000 households, farms, and businesses.\u00a0\u00a0A sampling of Jersey County’s 24-hour SCADA historical charts below tell a complete story of a digitally-controlled, high-performance butterfly valve utilized to control the fill of a GST (ground storage tank) at its Beatty Mound Pumping Station.\u00a0 The position of the valve (0-100%) is controlled so as to maintain the desired level in the tank, as well as to maintain 55 PSIG back-pressure during fill cycles:<\/p>\n
<\/a>Digitally-Controlled Quarter-Turn Valve. Valve: Jamesbury High-Performance Butterfly Valve. Actuator: Limitorque LY. SCADA Historical Charts (Left), Operator Setpoints (Right).<\/p><\/div>\n
The motorized valve will behave differently during a power outage, though, and it is always important for the Operator to understand this distinction.\u00a0 When a motorized valve loses line power, it will remain in the current position, since its motor requires power in order to turn.\u00a0 Therefore, during a power outage, the Operator would need to manually open or close the valve using the hand-crank.\u00a0 A solenoid-operated diaphragm valve, on the other hand, will generally seek a fully-closed or fully-open position upon loss of power, depending upon the specified configuration of the solenoid valve.\u00a0 For the diaphragm valve, the Operator would need to manually actuate a pilot\u00a0valve in order to actuate the valve during a power outage.<\/p>\n
Recently, in an effort to improve the performance of our digitally-controlled valve technology, we have investigated the use of a Quarter-Turn, V-Port\/Baffled Segmented Ball Valve as a replacement to the High-Performance Butterfly Valve.\u00a0 Due to the unique shape of its internal v-notched segmented ball and baffles, this valve offers increased Cv Flow Coefficient<\/a> linearity throughout the 90 degree turn.\u00a0 And because it presents less obstruction when fully-open, its Cv Flow Coefficient is generally higher than the Butterfly Valve for a given diameter.\u00a0 On 04 September 2014, we hosted a lunch-and-learn in Saint Louis (MO) where these valve and actuator technologies\u00a0were demonstrated live.<\/p>\n Would this technology help solve a control challenge in your potable water treatment or distribution system?\u00a0 Give us a call.\u00a0 Our Telemetry\/Controls Systems\u00a0are designed to leverage this exciting technology; and we’ll be glad to discuss in further detail.<\/p>\n Telemetry, SCADA, & Controls Newsletter<\/strong><\/p>\n Was this article helpful?\u00a0 Would you be interested in receiving updates such as these in our occasional email-delivered newsletter?\u00a0 If so, here’s our sign-up page:<\/p>\n Subscribe to\u00a0Navionics Research’s\u00a0“Telemetry, SCADA, & Controls Newsletter”<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" In the rural and municipal water industries, valve control of pressure and flow has often been accomplished using diaphragm-type valves.\u00a0 These types of valves can be tuned to provide altitude control at water towers, pumping stations, and custody-transfer valve stations.\u00a0 The valves offer a no-slam open\/close actuation and can be tuned to sustain a desired …<\/span> Read More →<\/span><\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":1563,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,16,18,19],"tags":[39,63,74,93,145,159],"class_list":["post-57","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-applications","category-sensors","category-valve-actuator","category-valves","tag-butterfly-valve","tag-feedback-control","tag-high-performance-butterfly-valve","tag-motorized-valve","tag-telemetry","tag-v-port-valve"],"_links":{"self":[{"href":"https:\/\/wireless-telemetry.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/57","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wireless-telemetry.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wireless-telemetry.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wireless-telemetry.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wireless-telemetry.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=57"}],"version-history":[{"count":0,"href":"https:\/\/wireless-telemetry.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/57\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wireless-telemetry.com\/blog\/index.php?rest_route=\/"}],"wp:attachment":[{"href":"https:\/\/wireless-telemetry.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=57"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wireless-telemetry.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=57"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wireless-telemetry.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=57"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}