How to prepare a request for quotation for a tank manway? A complete guide for customers

Process manways are an essential component of process tanks across many industries. In practice, however, requests for quotation often lack all the necessary technical data, which prolongs the quoting process and may lead to misunderstandings. Therefore, we have prepared a short list of key parameters to include in your inquiry to speed up the preparation of the quotation and ensure the correct selection of the manway for the installation’s operating conditions.

You can also use a ready-made RFQ template, which you will find at the end of this article.

Key information required for manway selection

Below are the key parameters for selecting a manway.

1. Manway type and geometry

Start by defining the basic design characteristics:

Manway type: (e.g. inspection, pressure, hygienic, etc.)
Shape: round, oval, or rectangular
Size: diameter or dimensions of the mounting opening

The shape and size of the manway directly affect service access to the tank and the structural strength.

2. Installation position

It is important to specify the mounting location of the manway on the tank:

In the tank roof (top manways): installation on the top head of the tank
In the tank side wall (side manways): installation on the cylindrical shell of the tank

This determines, among other things, the opening method, hinge design, and sealing type.

3. Tank material

Specify the construction material of the tank:

steel
plastic
concrete / cement
other material

This information is important for selecting the correct mounting flange and installation method.

4. Manway material

For stainless steel manways, specify the material grade - the most common are:

AISI 304/AISI 304L
AISI 316/AISI 316L

The material selection depends mainly on the aggressiveness of the medium and operating conditions.

5. Opening method

Manways can open:

outwards from the tank
inwards into the tank

The choice depends on available installation space and safety requirements.

6. Design parameters

It is also worth specifying:

Required flange height in millimeters (often referred to as parameter "H")
Handle material: plastic / stainless steel (INOX)

These parameters help match the manway to the tank design and operating conditions.

7. Gasket material

The choice of sealing material is critical for durability and tightness. Common materials include EPDM, NBR, VMQ (silicone), FPM (Viton).

The selection depends on temperature and the characteristics of the medium.

8. Process medium

Briefly describe the medium inside the tank, for example:

process water,
food product,
chemicals,
wastewater,
process mixtures.

This helps in selecting the appropriate gasket material and steel grade.

9. Operating parameters

To select the appropriate manway design, specify:

Operating pressure (bar)
Maximum / test pressure (bar)
Vacuum (negative bar values)
Operating temperature (°C)
Maximum temperature (°C)

Also indicate whether the maximum temperature occurs at maximum pressure (yes/no).

10. Compliance and additional requirements

Also specify:

whether PED certification is required (for installations ≥ 0.5 bar)
other requirements or additional equipment (e.g. safety features, locks, hygienic design, surface polishing, sight glass, ATEX)

11. Quantity

Finally, indicate the planned order quantity:

single unit,
larger production batch.

This allows for a more accurate cost estimation.

Sample request for quotation template

To make it easier to prepare your inquiry, below is a simple form that you can copy, complete, and send to us.

Type: [MODEL DESIGNATION (IF KNOWN)] 
Shape: [ROUND / OVAL / RECTANGULAR]

Size: [VALUES IN MILLIMETERS]
Installation position: [IN THE TANK ROOF (TOP MANWAYS) / IN THE TANK SIDE WALL (SIDE MANWAYS)]
Tank material: [STAINLESS STEEL / CONCRETE / PLASTIC / OTHER (WHICH?)]
Opening method: [OUTWARDS / INWARDS]
Steel grade: [AISI 304 / AISI 304L / AISI 316 / AISI 316L / OTHER (WHICH?)]
Flange height (parameter "H"): [VALUE IN MILLIMETERS]
Gasket material: [EPDM / NBR / VMQ / FPM / OTHER (WHICH?)]

Process medium description: [DESCRIPTION OF THE MEDIUM IN THE TANK]

Handle material: [PLASTIC / INOX]

Operating pressure: [VALUE IN BAR, E.G. 1 BAR]
Maximum pressure: [VALUE IN BAR, E.G. 2 BAR]
Vacuum: [NEGATIVE VALUE IN BAR, E.G. -0.5 BAR]

Operating temperature: [VALUE IN °C]
Maximum temperature: [VALUE IN °C]
Does the maximum temperature occur at maximum pressure: [YES / NO]

PED certification: [YES / NO]
Other requirements: [DESCRIPTION OF ADDITIONAL REQUIREMENTS (IF APPLICABLE)]

Quantity: [NUMBER OF UNITS PER ORDER]

Why it is worth providing complete data?

A complete request for quotation allows you to:

reduce the time needed to prepare a quotation,
select the correct manway design,
avoid later design changes,
optimize the cost of the solution.

If you are unsure about some of the parameters, it is worth consulting our sales team already at the inquiry stage. A well-prepared inquiry is the first step to efficient project execution.