How to Write a Technical RFQ for Flow and Level Instruments

What a Technical RFQ Must Achieve

A request for quotation, or RFQ, is the document that turns a need into comparable offers. For flow and level instruments, a good RFQ gives every supplier the same technical baseline so their proposals can be evaluated on merit rather than on the completeness of their guesswork. It also creates a record of what was requested, which protects you during later disputes.

The difference between a weak RFQ and a strong one is often just structure. A weak RFQ asks for a flow meter; a strong RFQ defines the process, the performance required, the environment, the documentation and the evaluation criteria. The effort spent writing it is repaid many times over during commissioning.

Section 1: Project and Application Context

Begin with the context so suppliers understand the duty. State the plant, the process, the fluid and the purpose of the measurement. Explain whether the instrument is for control, custody transfer, monitoring or safety, because this shapes the required accuracy and certification. A short narrative here prevents mismatched proposals later.

Include the expected service life and the maintenance philosophy. A supplier who knows the instrument must run for fifteen years selects differently from one who assumes a short campaign. Context also helps suppliers propose suitable options rather than the first model in their catalogue.

Section 2: Process and Environmental Data

Provide complete process data: fluid composition, pressure, temperature, flow or level range, viscosity, density and any solids or entrained gas. Specify ambient conditions, including temperature, humidity, corrosive atmosphere and hazardous-area classification. Missing data is the single biggest cause of unsuitable instrument selection.

• Fluid or media properties, including density, viscosity and corrosiveness.
• Operating pressure and temperature, plus upset conditions.
• Required measurement range and acceptable turndown.
• Line or vessel dimensions and mounting constraints.
• Ambient and hazardous-area classification.
• Power supply and output protocol available on site.

For flow applications, state the line size, orientation, straight-pipe availability and the expected turndown. For level, state the tank geometry, the presence of foam or vapour, and the mounting position. A Vega radar and an ultrasonic device may both be offered, and your data should let the supplier choose and justify the right technology.

Section 3: Performance and Materials

State the accuracy class, repeatability and response time required, and any custody-transfer or regulatory approval that applies. Define the wetted materials and specify the process connections and any hygiene or corrosion requirements. Where the fluid is aggressive, require the supplier to justify the material selection.

Include the enclosure rating, the cable entry and the local display expectations. These details matter in the field and are often overlooked in generic RFQs. A clear materials and performance section lets you compare offers directly, as with a Rosemount flowmeter where multiple lining and electrode options exist.

Section 4: Documentation and Certification

List the documents you expect with the delivery: calibration certificate, declaration of conformity, hazardous-area certificate, material certificates and the installation manual. State the language and format required. If traceability is important, say so and reference the relevant standard, such as the measurement terminologies maintained by the ISA or the communication profiles from the FieldComm Group.

Certification requirements should be stated once and unambiguously. Suppliers need to know whether they must provide third-party certificates or whether a manufacturer declaration suffices, because this affects both lead time and price.

Section 5: Commercial and Delivery Terms

Set out the commercial framework alongside the technical requirement: quantity, required delivery date, desired Incoterm, warranty period and payment terms. A separate table of RFQ sections helps suppliers respond line by line and avoids partial answers.

Ask suppliers to confirm compliance with each section explicitly rather than replying with a brochure. Where a requirement cannot be met, invite them to propose an alternative with a technical justification. This turns the RFQ into a conversation about engineering rather than a price-only contest.

An RFQ that cannot be answered line by line will not produce proposals that can be compared.

Evaluating the Responses

Evaluate technical compliance first and price second. A cheaper instrument that does not meet the accuracy or material requirement is not a saving. Score each response against the sections you wrote, and request clarification where answers are incomplete. Independent technical resources such as Flow Control Network can help you sense-check claims.

• Technical compliance against each RFQ section.
• Accuracy, materials and certification match.
• Lifecycle cost including maintenance and spares.
• Delivery, warranty and documentation completeness.

Consider lifecycle factors as well as purchase price. Maintenance, calibration interval and spare availability all affect the running cost. A turbine flowmeter and an Endress+Hauser flowmeter may both be compliant, but their ownership profiles can differ significantly.

Tying the RFQ to the Purchase Order

The RFQ becomes the technical baseline of the purchase order. Attach the specification, the clarification responses and the agreed datasheet so that the order is unambiguous. This continuity prevents the common problem of a supplier delivering something that meets the quotation but not the requirement.

Keep the evaluation record with the order for future reference. When the same instrument is purchased again, the RFQ saves time and reduces the chance of drift. To confirm availability or discuss a specific requirement, the team can be reached at /contact.