What Specs to Send a Peristaltic Pump Tubing Supplier: RFQ Checklist for Replacement Tubing

A supplier cannot quote a reliable replacement peristaltic tube from a message such as:

“Need silicone tube, 6 mm ID, for pump.”

That request leaves out the dimensions and operating conditions that determine whether the tube will actually fit, occlude, recover and survive in the pump head.

For repeat purchasing, the goal is not merely to find a tube that looks similar to the old one. The goal is to create a controlled replacement specification that can be sent to multiple suppliers, compared consistently and reused on future orders.

Decision Summary

A professional tubing RFQ should identify the pump and pump head, nominal ID, OD, wall thickness, dimensional tolerances, material grade, hardness when relevant, fluid and concentration, temperature, pressure, duty cycle, required length, documentation, sample quantity and repeat-order requirements. If the original tube is unknown, send both measured dimensions and a physical sample when possible. Do not approve a bulk order until a sample has passed fit, flow and short-service validation.

Affiliate disclosure: Some links in this guide are affiliate links. If you use them to place an eligible Alibaba order, Equipvia may earn a commission at no additional cost to you. Affiliate status does not determine the technical conclusions in this guide.

Why a Peristaltic Tube Needs a Full Specification

The tube is the pumping element.

Its dimensions determine how it sits in the pump head and how the rollers occlude it. Its material and hardness influence compression, recovery and fatigue. Its wetted surface must also tolerate the process fluid.

That means a replacement specification has three layers:

Mechanical fit
+
Process compatibility
+
Procurement / quality control

Ignoring any one of those layers can produce a tube that appears correct at receiving inspection but performs badly in service.

Current technical guidance from pump and tubing manufacturers consistently emphasizes ID, OD, wall thickness, material, temperature, media, pressure and installation as separate selection variables. citeturn272748search0turn272748search1turn272748search2

1. Identify the Pump and Pump Head First

Start every RFQ with:

Pump manufacturer
Pump model
Pump-head model
Number of channels
Original tubing part number, if known

The pump-head model matters more than the drive alone because the head defines the roller geometry, track gap, retention method and approved tubing family.

If the original manufacturer publishes a compatibility chart, attach or reference it.

Do not ask a supplier to infer the pump head from a photo if the model number is available.

Related guide: How to Match Peristaltic Pump Tubing to a Pump Head: Wall Thickness, Hardness & Occlusion

2. Specify ID, OD and Wall Thickness

These three dimensions should be written explicitly.

Inner diameter (ID):
Outer diameter (OD):
Wall thickness:
Units:

For a round tube:

Wall thickness = (OD − ID) ÷ 2

ID mainly controls the fluid passage.

OD and wall thickness strongly affect pump-head fit and occlusion.

A supplier should not be allowed to substitute by ID alone.

Current technical sources repeatedly warn that two tubes with the same bore can behave differently when wall thickness or OD changes. citeturn272748search0turn272748search5

3. Add Dimensional Tolerances

Nominal size is not enough for dosing or repeatable pump performance.

Add:

ID tolerance:
OD tolerance:
Wall-thickness tolerance:
Ovality / concentricity requirement, if critical:

Precision pump-tubing suppliers often control multiple wall measurements around the circumference because concentricity affects how consistently the tube compresses. Saint-Gobain, for example, publishes precision pump tubing with tightly controlled physical properties and optional multi-point wall measurement. citeturn272748search4

Do not copy a supplier's tolerance into your RFQ unless the process actually needs it.

Instead, define the performance requirement first.

For a simple transfer application, a wider tolerance may be acceptable.

For calibrated dosing, tighter dimensional consistency can be worth paying for.

4. Record Tube Number—but Never Use It Alone

If the system uses a common pump-tubing number, include it:

Tube number: #16 / #25 / #17 / #24 / etc.

But add the actual dimensions beside it.

Tube-number conventions are useful references, not a universal standard across every manufacturer. Current supplier guides explicitly recommend checking actual ID × OD × wall dimensions when sourcing across brands. citeturn272748search0turn272748search5

A useful RFQ line looks like:

Tube family: #25 reference
Nominal dimensions: 4.8 mm ID × 8.0 mm OD
Wall: 1.6 mm

That is much safer than sending only:

Need #25 tube

5. Specify the Exact Material or Allowed Alternatives

Avoid generic labels such as:

rubber
plastic
chemical-resistant tube
food-grade hose

Use a controlled material field:

Material / trade grade:
Cure system, if silicone:
Color / transparency:
Allowed alternative materials:
Not allowed:

Examples might include:

• platinum-cured silicone;
• PharMed BPT;
• Norprene / A-60-G;
• Tygon Chemical;
• FKM where chemically appropriate.

If substitution is allowed, require the supplier to identify the exact alternative formulation.

Do not accept “equivalent material” without a datasheet or defined grade.

6. Add Hardness When It Affects Pump Fit

Hardness is often expressed as Shore A durometer.

It affects how easily the tube compresses and how it recovers after the roller passes.

Include:

Hardness / durometer:
Test method:
Acceptable range:

ASTM D2240 is a widely used standard for durometer hardness.

Hardness should not be selected independently from wall thickness and pump-head geometry. Commercial pump-tubing guidance consistently treats hardness as one part of a larger mechanical fit problem. citeturn272748search1turn272748search4

If the OEM tube hardness is unknown, do not invent a target. Ask the supplier to provide the measured value and test a sample in the actual head.

7. Describe the Fluid Properly

“Water,” “solvent” or “cleaning chemical” is too vague.

Send:

Chemical name:
Concentration:
Mixture composition:
Additives:
Normal temperature:
Maximum temperature:
Contact time:
Cleaning / sterilization fluid:

This is especially important for sodium hypochlorite, sodium hydroxide, ethanol, acetone, DMSO and other chemicals whose compatibility changes by concentration or formulation.

Chemical compatibility should be evaluated against the exact process, not the polymer family name alone.

8. Give the Operating Duty

A tube used for five minutes per day and one used continuously are different procurement problems.

Specify:

Pump RPM:
Hours per day:
Continuous or intermittent:
Typical run length:
Start / stop frequency:
Expected replacement interval:

Repeated roller compression is what separates peristaltic pump tubing from ordinary transfer hose.

If the supplier claims an expected life, ask for the test conditions.

A statement such as “1,000 hours” is not meaningful without:

speed
pressure
temperature
fluid
pump head
failure criterion

9. Include Suction and Pressure Conditions

Send:

Suction lift or flooded suction:
Discharge pressure:
Maximum pressure:
Vacuum condition, if relevant:

Pressure and vacuum influence tube stress and pump performance.

Cleaning or sterilization cycles can also create more severe conditions than normal production, so they belong in the specification when relevant. citeturn272748search2

Do not solve a pressure problem by ordering a thicker wall unless the pump head is designed for that tubing family.

10. Define Documentation Requirements Before Quotation

Documentation can change the supplier pool dramatically.

Specify only what the process actually requires.

Possible fields include:

Certificate of Conformity
Lot traceability
Material declaration
FDA 21 CFR 177.2600 statement
USP Class VI evidence
ISO 10993 data
Extractables / leachables data
Sterilization compatibility
Food-contact documentation
Change notification

For general laboratory maintenance, many of these may be unnecessary.

For bioprocess, medical or regulated product-contact applications, they may be central to supplier approval.

A marketplace title saying “medical grade” or “food grade” is not equivalent to the requested documentation.

11. Define Length, MOQ and Packaging

Commercial details should also be standardized.

Ask for:

Sample length:
Production order length:
Cut length or continuous coil:
MOQ:
Meters per roll:
Packaging:
Label format:
Lead time:
Custom cutting available:

These fields matter because peristaltic tubing is a repeat-purchase consumable.

A low-MOQ product is useful during validation.

A larger coil may be more economical after the specification is locked.

12. Require a Sample Before Supplier Change

For a new supplier, a sample is part of engineering validation—not an optional sales convenience.

Use the sample to verify:

Fit in pump head
Normal closure
No twisting or migration
Priming
Measured flow
Pressure performance
Motor behavior
Short-term wear
Chemical exposure

If the tube passes, preserve the approved specification and supplier record.

If it fails, record why.

That turns future sourcing into a controlled replacement process rather than repeated trial and error.

A Copy-Paste RFQ Template

Use this as the minimum technical request:

Application: Replacement tubing for peristaltic pump

Pump manufacturer:
Pump model:
Pump-head model:
Original part number:

Tube number:
ID:
OD:
Wall thickness:
ID tolerance:
OD tolerance:
Wall tolerance:
Material / grade:
Hardness:

Fluid:
Concentration:
Normal temperature:
Maximum temperature:
Cleaning / sterilization fluid:

Pump RPM:
Duty cycle:
Hours/day:
Suction condition:
Discharge pressure:
Target flow:

Required documentation:
Sample length:
Production quantity:
MOQ:
Packaging:
Lead time:

Please confirm:
1. Exact material formulation
2. Dimensional tolerance
3. Pump-head compatibility basis
4. Chemical compatibility basis
5. Available quality documentation
6. Sample availability
7. Current price and quantity tier

13. Lock the Approved Specification for Repeat Orders

Once a sample has passed mechanical and process validation, do not let the next purchase start from zero.

Create a short approved-specification record:

Approved supplier:
Approved product / grade:
Pump-head model:
Tube number:
ID / OD / wall:
Tolerance:
Hardness:
Fluid / concentration:
Operating temperature:
Pressure:
Validated flow:
Approved sample date:
Lot / batch reference:
Replacement interval:
Required documents:

Then use that same record for future quotations.

If another supplier offers a lower price, compare against the approved fields one by one. The question is not whether the new tube is “similar”; it is whether every critical field is equivalent enough for the process.

This is also where change control matters. A supplier may change:

• raw-material source;
• cure system;
• hardness;
• extrusion tolerance;
• packaging;
• manufacturing location.

For ordinary maintenance, not every change requires formal validation. For calibrated dosing, regulated product contact or validated processes, even a small formulation or dimensional change may justify requalification.

Ask suppliers to notify you before changing any field that affects fit, chemical compatibility or documentation.

That simple step turns a successful trial into a repeatable procurement system rather than a one-off purchase.

A useful commercial rule is to separate qualification quantity from production quantity. The cheapest bulk offer should not be the first order. Buy enough for fit, flow, chemical exposure and short-duty testing first; then move to a larger coil only after the specification is approved. This keeps MOQ and unit price from overriding technical fit during supplier selection.

Current Alibaba Options by Sourcing Stage

Low-MOQ validation sample

Role: sample / small maintenance quantity before supplier approval.

Risk: confirm the exact dimensions and material variant before treating it as an OEM replacement.

Numbered silicone for repeat purchasing

Role: repeat or bulk replacement after the dimensional specification is validated.

Risk: tube number alone is not sufficient; confirm ID, OD, wall and tolerance.

A-60-G for a controlled material change

Role: alternative material when chemical resistance or flex-life requirements justify a change.

Risk: changing material requires renewed fit, flow and process validation.

Common RFQ Mistakes

Sending only a photo

Useful as supporting evidence, not as the specification.

Sending only ID

This omits the dimensions that determine pump-head fit.

Asking for “same as OEM”

The supplier still needs measurable fields.

Accepting “equivalent”

Require exact grade, dimensions and evidence.

Ordering bulk before trial

The cheapest per-meter quote can become expensive if the tube does not pump correctly.

Final Takeaway

A reusable tubing RFQ converts a vague maintenance purchase into a controlled technical specification.

The minimum sequence is:

pump head → ID / OD / wall → tolerances → material / hardness → fluid / concentration → temperature → pressure → duty cycle → documentation → sample validation → repeat order

Once those fields are locked, a buyer can compare suppliers on the same basis and replace tubing without restarting the engineering decision every time.

That is the core commercial strength of this Single Point: a validated tubing specification becomes a recurring procurement asset.