IN THIS GUIDE
A quotation for a petrochemical exhaust fan is only comparable when the process duty and project boundaries are clear. Terms such as "corrosion-resistant," "high-temperature" or "explosion-proof" do not describe a complete fan specification on their own. Use the checklist below to give suppliers a common basis and to identify items that require confirmation by the project engineer.
Representative product image: This 316L stainless-steel fan is a material example. Confirm alloy, lining, seals and project approvals against the actual process; this is not a project-specific installation.
01. Define the process gas and operating range
| RFQ item | What to provide | Why it matters |
|---|---|---|
| Gas composition | Known components, contaminants, moisture and any entrained liquid or solids | Supports materials and construction review. |
| Temperature | Normal, minimum, maximum and any defined upset condition | Changes fan density assumptions and material requirements. |
| Flow and pressure | Required volume flow, pressure basis, units and operating point | Lets the supplier evaluate the duty against an applicable fan curve. |
| Process cycle | Continuous or intermittent duty, start/stop frequency and control method | Helps define the drive and operating envelope. |
| Dust or droplets | Type, expected loading and whether accumulation or erosion is a concern | May affect wheel, casing, seals and maintenance requirements. |
02. State the area and compliance requirements precisely
Provide the project's area classification, gas group, temperature class and applicable site or jurisdiction requirements when they have been established by the responsible project authority. Identify which documents or third-party certificates are required for the complete fan assembly. A motor marking or certificate alone should not be presented as proof that every fan component and the finished assembly meet the project requirement.
If the classification or required approval is still being developed, mark it as an open item. Do not ask a supplier to infer a hazardous-area requirement from the industry name or location.
03. Specify materials and mechanical details
- Identify gases or liquids that drive corrosion risk and state any material, coating or lining requirements already approved by the project.
- Describe the installation orientation, support arrangement, inlet and outlet direction, duct connection and access available for maintenance.
- State shaft-seal, bearing, coupling, guard, drain or inspection requirements that apply to the process.
- Provide the available electrical supply, motor control method, starting approach and project electrical data.
- List noise, space, weight, lifting or spare-parts requirements that affect the installation.
04. Agree on the offer and acceptance documents
Ask each supplier to state the offered fan configuration, operating point, assumptions, exclusions and deviations. Define which performance data, drawings, material records, inspection records, test documents, manuals and spare-parts lists must be delivered, and when they are needed. If field acceptance measurements are required, state the measurement method, points and acceptance basis in the RFQ rather than leaving them ambiguous.
05. RFQ package buyers can send
- Process description and gas data sheet, including normal and upset conditions.
- Required flow, pressure type and value, temperature range and duty cycle.
- Area classification and the exact project approval documents required.
- General-arrangement drawing, duct sketch, connection details and installation photos.
- Motor and electrical data, control method, materials requirements and available space.
- Required tests, inspection stages, documentation, delivery boundary and spare parts.
Frequently asked questions
Can a supplier choose the fan from flow alone?
No. Flow must be considered with pressure, gas condition, installation layout, controls and the required operating range. Provide a defined duty point and state how it was determined.
Does "corrosion-resistant fan" specify a material?
No. Identify the process gas and approved material or coating requirements. The appropriate construction depends on the chemistry, concentration, temperature, moisture and project limits.
Is an explosion-proof motor enough for a hazardous process?
No blanket conclusion should be made from the motor alone. Confirm the applicable project classification and required evidence for the complete fan configuration with the responsible engineer and supplier.
Related references
- Industrial fan material selection guide
- How gas temperature affects industrial fan performance
- Industrial fan technical documentation package
Need to prepare an RFQ? Send the process duty and project document list to sales@qiyuefan.com. QIYUE FAN can review the information needed to prepare a project-specific offer.