Industrial Butterfly Valve RFQ Guide

Define the piping interface before comparing models

Butterfly valve names alone do not establish interchangeability. State whether the project requires a wafer, lug, double-flanged, single-flanged, butt-welded or another documented body style.

Include the mating flange standard, flange bore or pipe inside diameter when available, and any project face-to-face or dimensional drawing requirement. These details allow the published valve reference and the actual pipeline interface to be reviewed on the same basis.

• Nominal size in DN or NPS
• Pressure designation and referenced standard
• Body style and required connection
• Mating flange or adjoining pipe information
• Installation-space or face-to-face requirement

Separate construction requirements from document requirements

List required body, disc, shaft, seat, liner, packing and fastener materials separately where the project specifies them. A general material name should not be used to infer every wetted or pressure-containing component.

If the project refers to API, AWWA, EN, ISO, ASME, DIN, BS or JIS, include the exact designation and edition stated by the buyer. List certificates, reports and inspection records in a separate document field because a standard reference is not evidence that a certificate is available.

Describe the operating duty without guessing a valve selection

Provide the medium, working temperature, normal and maximum pressure conditions, flow direction requirement, shutoff direction and any dead-end service requirement supplied by the project.

Actuation must be reviewed as part of the valve assembly. State the available power or control signal, preferred fail position when applicable, environmental conditions and any required actuator attachment standard.