Industry
Air-operated double diaphragm (AODD) pumps are typically rated using water at standard conditions. As fluid viscosity increases, the pump flow rate decreases due to higher internal friction and limitations in diaphragm response.
This page provides viscosity correction tables for AODD pumps, allowing you to estimate expected flow reduction across a range of pump sizes and fluid viscosities.
Use this data as a preliminary sizing and comparison tool when evaluating AODD pump performance with viscous fluids.
1/4" Inlet/Outlet Ports
Viscosity of Pumped Product
1 CentiPoise (cP)
60 cP
115 cP
170 cP
225 cP
280 cP
335 cP
390 cP
445 cP
500 cP
Example
Higher The Viscosity, Lower The Flow
Estimated Performance Decrease
No effect - 100%
Reduce By 10%
Reduce By 20%
Reduce By 30%
Reduce By 40%
Reduce By 50%
Reduce By 60%
Reduce By 70%
Reduce By 80%
Reduce By 90%
A 1/4" AODD pump rated at 10 L/min handling a 170 cP fluid:
30% reduction → ≈ 7 L/min actual flow
3/8" Inlet/Outlet Ports
Viscosity of Pumped Product
1 CentiPoise (cP)
110 cP
220 cP
330 cP
440 cP
550 cP
660 cP
770 cP
880 cP
1000 cP
Example
Higher The Viscosity, Lower The Flow
Estimated Performance Decrease
No effect - 100%
Reduce By 10%
Reduce By 20%
Reduce By 30%
Reduce By 40%
Reduce By 50%
Reduce By 60%
Reduce By 70%
Reduce By 80%
Reduce By 90%
A 3/8" AODD pump rated at 30 L/min handling a 220 cP fluid:
20% reduction → ≈ 24 L/min actual flow
1/2" & 3/4" Inlet/Outlet Ports
Viscosity of Pumped Product
1 CentiPoise (cP)
550 cP
1,100 cP
1,600 cP
2,200 cP
2,700 cP
3,300 cP
3,900 cP
4,500 cP
5,000 cP
Example
Higher The Viscosity, Lower The Flow
Estimated Performance Decrease
No effect - 100%
Reduce By 10%
Reduce By 20%
Reduce By 30%
Reduce By 40%
Reduce By 50%
Reduce By 60%
Reduce By 70%
Reduce By 80%
Reduce By 90%
A 3/4" AODD pump rated at 60 L/min handling a 2,200 cP fluid:
40% reduction → ≈48 L/min actual flow
1" Inlet/Outlet Ports
Viscosity of Pumped Product
1 CentiPoise (cP)
1,100 cP
2,200 cP
3,300 cP
4,400 cP
5,500 cP
6,600 cP
7,700 cP
8,800 cP
10,000 cP
Example
Higher The Viscosity, Lower The Flow
Estimated Performance Decrease
No effect - 100%
Reduce By 10%
Reduce By 20%
Reduce By 30%
Reduce By 40%
Reduce By 50%
Reduce By 60%
Reduce By 70%
Reduce By 80%
Reduce By 90%
A 1" AODD pump rated at 150 L/min handling a 5,500 cP fluid:
50% reduction → ≈ 75 L/min actual flow
1.5" Inlet/Outlet Ports
Viscosity of Pumped Product
1 CentiPoise (cP)
1,600 cP
3,300 cP
5,000 cP
6,600 cP
8,300 cP
10,000 cP
11,600 cP
13,300 cP
15,000 cP
Example
Higher The Viscosity, Lower The Flow
Estimated Performance Decrease
No effect - 100%
Reduce By 10%
Reduce By 20%
Reduce By 30%
Reduce By 40%
Reduce By 50%
Reduce By 60%
Reduce By 70%
Reduce By 80%
Reduce By 90%
A 1.5" AODD pump rated at 200 L/min handling a 10,000 cP fluid:
60% reduction → ≈ 80 L/min actual flow
2" Inlet/Outlet Ports
Viscosity of Pumped Product
1 CentiPoise (cP)
2,000 cP
4,000 cP
6,000 cP
8,000 cP
10,000 cP
12,000 cP
14,000 cP
16,000 cP
18,000 cP
Example
Higher The Viscosity, Lower The Flow
Estimated Performance Decrease
No effect - 100%
Reduce By 10%
Reduce By 20%
Reduce By 30%
Reduce By 40%
Reduce By 50%
Reduce By 60%
Reduce By 70%
Reduce By 80%
Reduce By 90%
A 2" AODD pump rated at 350 L/min handling a 14,000 cP fluid:
70% reduction → ≈ 105 L/min actual flow
3" Inlet/Outlet Ports
Viscosity of Pumped Product
1 CentiPoise (cP)
2,700 cP
5,400 cP
8,100 cP
10,800 cP
13,500 cP
16,200 cP
18,900 cP
21,600 cP
24,000 cP
Example
Higher The Viscosity, Lower The Flow
Estimated Performance Decrease
No effect - 100%
Reduce By 10%
Reduce By 20%
Reduce By 30%
Reduce By 40%
Reduce By 50%
Reduce By 60%
Reduce By 70%
Reduce By 80%
Reduce By 90%
A 3" AODD pump rated at 600 L/min handling a 15,000 cP fluid:
90% reduction → ≈ 60 L/min actual flow
