Valve Position Indicator – A Complete Guide

Ranging from thousands of products ranging from flowmeters, transmitters, gauges, and valve position indicators, BCST manufactures and supplies them to the industries according to their industrial applications. As a result, the whole package is available to measure the flow, position the valves, and control the solution.

Following are the frequency asked questions and their answers regarding the valve position indicator:

What is the valve position indicator?

The valve position indicator is an accurate gear motor along the display showing the particular volume of the oil throughout the unit. The gear wheels keep rotating depending on the flow and its direction. The small gearbox is already built-in along with the gear ratio, whose selection is according to the displacement of the actuator. It moves forward the movement of the gear motor towards the indicator shaft. Mechanically, there is no connectivity between the indicator shaft and gear motor. The rotation of the hydraulic gear wheels is transferred towards the indicator shaft through the magnetic clutch. It helps in eliminating the possibility of the leakages externally, if any. An indicator’s arrow moves in the scale that you can adjust between 75 degrees to 200 degrees. The small indicator disc is mounted tightly on the indicator shaft serving the purpose of the leakage indicator.

What are the advantages of using a valve position indicator?

• Reliability on valve position indicator: You can depend on the highly accurate position of the signal by the valve position indicator. It is adjustable while receiving close or open signals whenever the value reaches the last position.
• Valve position indicator suitable for all manual multi-turning valves: The body gets attached to the general bracket valve. You can mount it with any multi-turning valve installed in a minimum time. Typically, the valve position indicator is available with the blind adaptor.
• Valve position indicator causes a reduction in the maintenance costs: There are sensors in the valve position indicator that protect the external factors. The valve position indicator is designed so that it is durable enough and requires less maintenance.
• Saving the investment cost by decreasing the requirement of actuators: Whenever you need a valve position signal, you don’t need to buy the actuators. Valve position indicator helps you in saving regarding the cost for investing and maintenance.
• The valve position indicator applies to explosive hazardous areas: The valve position indicator can perform well in an endangered environment. Therefore, the valve position indicator has received the certificates and approvals.

How to install the valve position indicator?

• Installation of valve box adaptor:
• removing the lid of the present valve box
• fix the adaptor of the valve box on the opening of the valve
• installation of the including stem:
• attachment of the stem with the box of the internal valve
• installation of stem bushing:
• sliding the bushing down towards the stem
• save the bushing in the space of two, 1 /4-20 screws of the socket head cap
• Installation of the indicator along with the gasket and base:
• Sliding off the components downwards onto the stem
• Aligning of the pin (of plastic) along with the slot inside the bushing
• Make sure that the indicator is in such a direction from where you intend to see it. It is important to keep turning the valve box adaptor to receive the actual orientation.
• Check the position of the valve is in a close direction, and the Reading on the indicator is 0000.0
• Tight all the screws of the indicator’s collar compared to the stem
• Installing the silicone enclosing sleeve:
• The stem on the top of the indicator requires greasing
• Keep sliding the silicone sleeve down on the indicator and stem
• Start the silicone sleeve down on the lip surrounding the perimeter of the indicator enclosing the base for sealing the unit.
• Installation of the 2 inches working nut:
• Alignment of the tapering flats of the steam with the similar feature inside the nut
• Securing the 2 inches nut working while tightening the nut, there is no possibility of turning the stem.
• Turning the stem for the verification of the correct actuation of the indicator’s unit
• Replacement of the lid of the valve box and filling according to the desired height.
• Typically, this is flush along and above the adaptor of the valve box.

How is the operation of the valve position indicator?

• Turning on the working nut in such a direction as towards the base for opening and closing the valve.
• Whenever there is an opening and closing of the valve, the mechanical position indicator starts displaying the turns automatically where the valve is set at the moment.
• The closing valve shows the Reading 0000.0 whenever you are following the instructions properly.
• The sticker below the enclosing of the silicone sleeve shows how many turns are in need for opening the valve.
• When the Reading on the digital indicator is the same as the sticker, the valve is open completely.

What are the maintenance tips regarding the valve position indicator?

• Keep lubricating the stem that is passing by the indicator and enclosing the dielectric and food-grade. Clear greasing prevents sticking of the silicone sleeve during actuation.
• You are checking the bronze bushing and stainless stem occasionally. If you observe excessive wearing while these parts are in contact, make sure that the installation of the stem is along the valve stem. Also, ensure that the alignment of these components is appropriate.
• After installing the valve position indicator for many years, there can be a yellowish tint start on the enclosing of the silicone sleeve. It increases due to exposure to sunlight. Therefore, you need to replace and purchase the sleeve or indicator unit separately.

What are the specifications of the valve position indicator?

What are the functions of the valve position indicator?

• Indicating visual position: the valve position indicator helps determine the valve’s work through the visual indicator. The location of the visual indicator is on the top of the enclosure of the valve position indicator.
• They are receiving electrical feedback from several devices such as sensors, internal switches, and transmitters. It facilitates the position of the valve towards the control room by directing the electrical signals. These signals are constantly encoding the position.
• A junction box helps encode the position of the switches and platform for mounting the solenoid valves. It also gives terminal points to wire for suitable signals towards the enclosure.

Which type of valve position indicator is found in industrial plants?

The standard type of valve position indicator found in the industrial plants has fulfilled the two significant specifications. First, it includes surrounding conditions regarding the installation of the valve position indicator. The second specification is the endangerments where hazardous gases are present in the industrial plants. In addition, the valve position indicator is reliable enough, has a long span, and is particularly suitable for severe environments.

Environmental conditions:

General-purpose and hazardous areas:

• Typical on-off indicator in black/yellow or red/green patterns
• Two mechanical switches
• Enclosure of aluminum
• Direct shaft to the mounting of the actuator
• Mounting indoors or outdoors

What are the features of the valve position indicator?

• Rating of electrical switch includes rating AC/DC and AC/DC voltage at the maximum level.
• Availability of the mounts: for the standard and special shafts
• Intrinsically safe (IS): is a unique technique regarding the safety and protection of electrical equipment in endangered areas
• Products are explosion-proof: those who can survive in hazardous surroundings and are resistant to corrosion or chemical.
• We are connecting with the valve position indicator: linking with the network and monitoring the devices.
• Backlit or illuminating position indicators: are helpful to dim the lighting or non-existing ones.
• Adjustable products for the field: they are easy to bring in the area.

What are installation instructions for the ball valve position indicator?

• Determine the actual location of the valve position indicator on the panel of the pump
• Cut the opening in a rectangular shape using the dimensions and holes of screws in the pump panel.
• Install the valve position indicator by the front side of the front panel. Also, join the screws, lock washers, and nuts available.
• After the installation of the valve position indicator, now it’s time to install the ball valve below:
• Keep determining the number of turns of the handwheel required by the ball valve for completely opening and closing.
• It would help if you turned the handwheel of the valve position indicator until and unless there is a red line that shows the half-opening of the valve.
• Now the installation of the valve position indicator is complete and ready for the link.

What is the function of valve positioners?

Usually, the installation of the valve positioners is above the case of the pneumatic actuator for the control valve or at the corner of the shaft (for rotating the control valve). Their connection is mechanical with the stem of the valve or shaft. The feedback linkage works so that the processor’s controller guides the positioner for changing the position. In return, the feedback linkage receives assurance from the positioner whenever there is a change in the positioning of the valve. It is kind of sense in changing the magnitude with the position.

What are the types of valve positioners?

There are four types of valve positioners. Electronic, pneumatic, electro-pneumatic and digital. The pneumatic positioners receive and send the pneumatic signals. They are safe and deliver a large amount of force for closing the valve. Single or 3-way pneumatic positioners consume or send the air from the only single side of the valve actuator. The electrical valve positioners keep sending and receiving the electrical signals. The electronic valve positioner converts the actual controlling signal equal to the pneumatic signals. It uses a mixture of air and electricity. The digital positioner is also known as a smart positioner. It also uses the microprocessor for multiple purposes, such as positioning the valve actuator and monitoring and recording the data. Their accuracy rate is high, consumes less air than the analog positioners, and permits digital diagnostics online.

Why use the valve positioner in an industrial application?

• More accurate controlling: The valve positioner knows the exact location of the valve. So, it provides the precise control that you receive from the actuator itself.
• Faster controlling: The positioners provide assistance to the control valves for responding faster whenever the process variable changes, decreases the time of using the system above or below the setpoint, and response speed also increases whenever there is a change in the process. It also permits the loading and venting faster.
• Consistency in the position of the valve: The differential pressure varies inside the valve, showing that there is no stability in the control loop. The solution to stabilize the position of the valve is the positioner.
• More flexibility in the functionalities and configurations: The positioner helps maintain the distance between the control valve and controller.
• Reducing the effects of friction: Friction inside the valve’s stem causes the dead band that causes the reduction in productivity, especially for the packing material with high temperature, including graphite.
• Maintaining the distance between the controller and control valve: Permits an extensive range of flow variations, including the working and traveling less than 10%.

What are the issues with the manual valve position indicator?

In the industries, awareness regarding the valve’s status is essential to prevent injury and damage to the equipment. This is why the use of a valve position indicator helps in communicating regarding manually controlling the opening and closing of the valve towards the control room. Following are some of the problems that industries face while using the manual valve position indicator.

The connectivity of these issues is with the self-made brackets, particularly for the valve position indicators that include:

• Dislocating the switches with ease and require adjustments again
• Indicates accuracy at the low level
• Durability is low
• Performance is poor, whatever is the climatic conditions and weather changes.
• Vibration resistance is just average
• Existing of the distortion present in the cables

What are the applications of valve position indicators?

• In wells of oil and gas
• Mining
• Refineries
• Facilities to store the fuel
• Seaside grain and multiple loading docks
• Chemical and petrochemical plants
• Facilities for treating the wastewater
• Useful in the whole network of production of oil and gas pipelines
• Blending and batching of the paints
• Beverage and food industries
• Plants for manufacturing the pesticides, drugs, and pharmaceuticals
• Textile, finishing, and dyeing plants

What are the types of valve position indicators?

The valve position indicator is suitable for both rotatory actuating valves and linear actuating valves. In addition, it facilitates with typically two options of switching that are:

• Non-contact switches: The purpose of using the non-contact switch is to monitor the opening and closing of the machines’ doors and other equipment. There is no need for physical contact between an actuator and the control. The housing is n rectangular or cylindrical, and construction is made of stainless steel or plastic. The purpose of designing these switches is to protect the machines and labor force. The sensing distance in the non-contact switch is comprehensive than 10mm and can handle the misalignment even after the sensing.
• Mechanical switchers: The activation of the mechanical switchers by the energizing arms whose connection is with the moving stem or the shaft. There is an automatic linking towards the actuator.

How is the display of the valve position indicator?

There is a large LED that displays the position of the valve. The valve position indicator has an internal source of current working independently. It can select the switch of 4mA for closing the valve and 20mA for opening the valve. You can mount the valve position indicator on the valve or near it to be easy to use and visible. Its position must be 3 meters away from the valve in any direction. There is also an availability of extension wires where there is a need for more length. Some of the valve position indicators display the information on the rotating dials or sliding scale. The availability of the valve position indicator is with the position transmitters sometimes. It helps provide the signals at a continuous level regarding the opening, closing, and intermediate position of the valve.

What are troubleshooting issues in valve position indicator and corresponding solutions to it?

How is the wiring of the valve position indicator?

The availability of the valve position indicator is with the waterproof disconnecting cables. If the valve position indicator mounting is on the valve, then 8-foot and 2-foot cables along the pigtails. You can connect it with the junction box that the customer will give you. If the mounting valve position indicator is far away from the valve, then the 8-foot cable’s connection is with the powerhead of the Sealed Motor Valve (SMV). For the greater distances, you can use and connect the extra 8-foot. The proper and correct is very necessary for the working of the Sealed Motor Valve. Select the correct wire size for the 24V DC power supply to the powerhead according to the distance and number of valves present. The valve position indicator is always ready to use because its shipment is with the box and the Sealed Motor Valve.

Final thoughts:

The valve position indicator is the switching device working electrically and mounting on the valve actuator directly. Whether you are looking for a valve position indicator or any other product, BCST and its team members are always available for your assistance. Please place your order today and receive it within seven working days.