How to Select Tubing for Your Peristaltic Pump

Peristaltic pumps have one wetted part: the tube. Flow accuracy, contamination risk, and service life all depend on choosing the right tubing. Here's what to evaluate.

1. Tubing Dimensions

All three measurements must match your pump head.

Parameter What It Controls Selection Rule
Inner Diameter (ID) Flow rate per revolution Larger ID = higher flow
Outer Diameter (OD) Fit in pump head channel Must match pump head geometry exactly
Wall Thickness Compression, pressure rating, fatigue life Standard: 1.6 mm / Heavy: 2.4 mm

Common # Size Reference (Masterflex System)

The # numbering system (e.g., 13#, 15#, 25#) originated from Masterflex/Cole-Parmer. Each number encodes a fixed ID/OD/wall combination. Two wall thickness series exist: standard wall (1.6 mm) and heavy wall (2.4 mm) — the same ID gets a different # number depending on wall thickness (e.g., ID 4.8 mm = 25# standard wall vs. 15# heavy wall).

# Number ID (mm) OD (mm) Wall (mm) Typical Use
13# 0.8 4.0 1.6 Low-flow lab dosing
14# 1.6 4.8 1.6 Low-flow lab
16# 3.1 6.4 1.6 Low-to-mid flow
25# 4.8 8.0 1.6 Mid flow, standard wall
17# 6.4 9.6 1.6 Mid flow
18# 7.9 11.1 1.6 Mid-to-high flow
19# 9.5 12.7 1.6 High flow, standard wall
26# 12.7 15.9 1.6 High flow industrial
27# 15.9 19.1 1.6 Large flow industrial
73# 1.6 6.4 2.4 Low flow, heavy wall
82# 3.1 8.0 2.4 Mid-low flow, heavy wall
15# 4.8 8.0 2.4 Mid flow, heavy wall
24# 6.4 11.1 2.4 Mid flow, heavy wall
35# 7.9 12.7 2.4 Mid-high flow, heavy wall
36# 9.6 14.4 2.4 High flow, heavy wall

Regional usage of the # system:

🇺🇸 North America
Standard. Masterflex # system is the dominant convention across labs and industry.
🇨🇳 China
Widely adopted. Most domestic pump manufacturers follow the # system; some label tubing directly as ID/OD/wall.
🇪🇺 Europe
Mixed. Watson-Marlow uses proprietary numbering; others label tubing as ID×OD in mm.

ⓘ When sourcing across brands, always verify by actual dimensions (ID × OD × wall in mm) — # numbers are only reliable within the same brand's system.

2. Tubing Material

Material Temp Range Chemical Resistance Best For Do NOT Use For
Silicone -60°C to +200°C Moderate Aquariums, homebrewing, general lab water/buffer transfer Oils, fuels, solvents, concentrated acids/bases
Platinum-Cured Silicone -60°C to +200°C Moderate Pharma, IV fluids, food & beverage, any FDA/GMP process Same chemical limits as silicone
Tygon® (PVC) -50°C to +74°C Good (grade-dependent) General lab chemical transfer, dilute acids/bases Autoclave; food/pharma contact (plasticizer risk)
Norprene® -60°C to +135°C Very good Chemical dosing, oil transfer, autoclave-required processes Aromatic/chlorinated solvents at high temp
Viton® (FKM) -20°C to +200°C Excellent Fuels, aggressive solvents (toluene, DCM), hydraulic fluids Ketones, esters, amines; needs higher-torque motor
PTFE -200°C to +260°C Near-universal Ultra-high-purity transfer, low-speed analytical instruments High RPM / continuous duty — fatigues rapidly
Marprene® -20°C to +100°C Good 24/7 high-RPM industrial processes (5–10× longer life than silicone) Non-Watson-Marlow pump heads — proprietary sizing

Quick pick: Water/food/pharma → Platinum Silicone  |  Oils/mild chemicals → Norprene  |  Aggressive solvents/fuels → Viton  |  24/7 high-speed → Marprene

3. Sterilization Compatibility

Method Silicone Platinum Silicone Tygon Norprene Viton
Autoclave (121°C)
Chemical (bleach, IPA, H₂O₂) ✅* ✅* ✅* ✅* ✅*
Gamma irradiation ⚠️
UV ⚠️

*Verify concentration and contact time against compatibility data.

4. Key Operating Factors

Factor Impact Recommendation
High RPM (>300) Accelerates fatigue Use heavy-wall or Marprene tubing
High back-pressure Increases compression stress Use heavy-wall (2.4 mm+) tubing
Elevated temperature Reduces elasticity Add 20°C safety margin to rated max
Dry running Destroys tubing within minutes Always prime before starting
Abrasive fluids Internal wear Prefer silicone or PTFE (smooth bore)

5. End-of-Life Signs & Replacement Planning

Replace tubing when you see:
  • Visible cracking, flattening, or permanent deformation
  • Flow rate drops without changing pump settings
  • Fluid leaking from the pump head
  • Tubing feels stiff, sticky, or discolored
Extend tubing life by:
  • Never dry-running the pump
  • Releasing roller tension when idle for extended periods
  • Storing spare tubing away from UV, heat, and ozone

Shop Peristaltic Pump Tubing & Accessories

U.S. Solid offers replacement tubing and accessories sized to fit our M6 series peristaltic pump heads, including platinum-cured silicone tubing in multiple sizes, tube clamps, and straight connectors.

Browse Peristaltic Pump Accessories →

Back to blog