Pneumatic Control Valve RFQ: Air Supply and Accessories

Prepare a pneumatic control valve RFQ covering air supply, fail action, positioner signals, solenoid valves, limit switches and documentation.

ZHONGYUE VALVE

11/11/20262 min read

Pneumatic diaphragm control valve with mounted positioner and air tubing

Two quotations for the same valve size can include very different pneumatic packages. One may include a positioner, filter regulator and feedback switches; another may exclude them. A complete pneumatic control valve RFQ defines the duty, utility supply, control interface and required response to each failure condition. This guide helps buyers make those differences visible before placing an order.

Specify air supply and actuator requirements

State the minimum, normal and maximum instrument-air pressure available at the valve location. Identify the required air quality, ambient temperature range and any project restrictions on tubing, fittings or exhaust arrangements. Do not substitute the plant-header pressure for the minimum pressure available after the local regulator and distribution losses.

Provide the maximum relevant shutoff differential pressure and the required valve action. Ask the supplier to identify the actuator type, sizing basis, spring arrangement where applicable and required supply pressure. The actuator must be assessed with the selected valve and service conditions; a preferred actuator size alone is not a complete specification.

Define failure cases individually

Specify the required valve position on loss of air, loss of electrical power and loss of control signal separately. “Fail closed” is incomplete if the quotation does not identify the initiating failure and the arrangement that achieves the action. A double-acting actuator does not inherently establish a predictable fail position without an appropriate system design.

If an air receiver, lock-up valve, volume booster, quick-exhaust valve or other accessory is required, describe its intended function. For a stroking-time requirement, state the direction of travel, start and end points, test supply pressure and whether the measurement is under a specified load. Establish the acceptance method rather than assuming that a catalogue speed applies to the installed assembly.

List signals and accessories line by line

A positioner regulates actuator pressure to make valve position follow the control command; Emerson provides an overview of valve positioner operation. Specify the input signal and any required communication protocol, position feedback, electrical connection and mounting arrangement. Confirm which functions are included in the quoted model.

For solenoid valves, identify supply voltage, required de-energized action and the project control philosophy. For limit switches or position transmitters, specify the number and type of outputs, electrical ratings and signal destinations. Identify whether the local indicator and manual override are required and how an override should be managed.

State the actual hazardous-area classification and required approval scheme when applicable. An enclosure protection rating is not an explosion-protection approval, and a component certificate does not automatically establish certification of the complete assembly. Request the documents that apply to the offered configuration.

Compare the package and its documents

Ask each bidder to return an accessory list with manufacturer, model, quantity, included scope and exclusions. Request a pneumatic schematic, electrical connection information, assembly drawing and agreed functional-test records. Check that the schematic and quoted fail actions agree.

Complete the process datasheet as well as the accessory schedule. Our control valve flow-characteristic guide explains the operating cases needed for trim selection. Send both schedules to WENZHOU ZHONGYUE VALVE TECHNOLOGY CO., LTD. for a project-specific quotation discussion. Confirm accessory availability and documentation in the final agreed offer.

Zhongyue High Quality Valve Manufacturer

The products are exported to the United States, Europe, the Middle East, Southeast Asia, Russia and other countries and regions, reliable quality and reasonable price. Reliable quality and reasonable price are the basis of our continuous development.

Contact

Get in touch Please leave the questions you need to consult, later we will have a professional technical team to contact you.

Email: sales@hizhongyue.com

Tel: +86 0577-28828932

WhatsApp/WeChat: +86 15658617888