What to Do When a Client Specifies a Random Packing Size That Is Not a Standard Manufacturing Size
Industrial RFQs sometimes specify unusual packing dimensions.
The requested size may come from:
- an old drawing;
- another supplier;
- an existing tower sample;
- a consultant specification.
The problem appears when the exact dimension is not part of the manufacturer’s normal product range.
Should the supplier manufacture a custom tool?
Should the closest standard size be offered?
The answer depends on why the dimension matters.
First Determine Whether the Dimension Is Functional
Some dimensions are essential because they affect:
- tower hydraulics;
- support openings;
- replacement compatibility.
Other dimensions may simply reflect the original supplier’s catalogue.
Therefore, the first question is:
Does the process actually require this exact dimension?
Replacement Projects Need More Caution
If the new packing will be mixed with existing packing, dimensional compatibility may be important.
Different sizes can affect:
- bed uniformity;
- void fraction;
- liquid distribution.
For complete bed replacement, there may be more flexibility.
Standard Sizes Usually Have Advantages
Using a standard product can provide:
- lower MOQ;
- shorter production time;
- lower tooling cost;
- established quality data.
Therefore, a nearby standard size may be commercially attractive.
But it should not be substituted without engineering review.
Compare Performance, Not Just Dimensions
If an exact requested size is unavailable, compare the proposed standard alternative in terms of:
- surface area;
- void fraction;
- pressure drop;
- bulk density;
- flooding behavior.
A nominally close dimension may still have significantly different geometry.
Custom Tooling Can Be Justified for Large Projects
For substantial quantity, a new mold may be economically reasonable.
Before doing so, confirm:
- annual volume;
- total project quantity;
- tolerance;
- material;
- required test data.
Custom tooling for a very small order may be commercially unrealistic.
Explain the Difference Clearly
The supplier should state:
- requested size;
- available standard size;
- key dimensional difference;
- expected technical implication.
The customer can then decide whether exact duplication is truly necessary.
Final Engineering Principle
A nonstandard packing dimension should trigger an engineering comparison, not an automatic rejection or silent substitution.