AODD Pump Selection Guide - Sizing and Application

Selection Process Overview

Step-by-Step Selection

1. Define process requirements
         ↓
2. Calculate hydraulic requirements
         ↓
3. Check suction conditions
         ↓
4. Select pump size
         ↓
5. Choose materials of construction
         ↓
6. Verify air supply capacity
         ↓
7. Consider accessories needed
         ↓
8. Final verification

Step 1: Process Requirements

Information Needed

Fluid Properties Checklist

□ Fluid name/composition
□ Specific gravity
□ Viscosity (at operating temperature)
□ Vapor pressure
□ Solids content (% and particle size)
□ Abrasiveness
□ Chemical composition
□ Temperature range (min/normal/max)

Step 2: Hydraulic Calculations

Total Dynamic Head (TDH)

TDH = Hstatic + Hfriction + Hpressure

Where:
Hstatic = Static head difference (discharge - suction elevation)
Hfriction = Pipe friction losses
Hpressure = Vessel pressure difference

Flow Rate with Safety Factor

Design Flow = Required Flow × 1.2

Example:
Required: 100 LPM
Design: 100 × 1.2 = 120 LPM

Pressure Calculation

Discharge Pressure Required = TDH × SG × 0.0981 (bar)

Or: Discharge Pressure = TDH × SG × 0.433 (psi)

Example:
TDH = 30 m, SG = 1.2
Pressure = 30 × 1.2 × 0.0981 = 3.53 bar

Step 3: Suction Conditions

NPSHa Calculation

NPSHa = (Patm - Pvapor)/(ρ×g) + Hstatic(suction) - Hfriction(suction)

Suction Lift Verification

Suction Design Rules

✓ Keep suction lift as low as possible
✓ Use flooded suction when available
✓ Minimize suction line length
✓ Suction pipe ≥ pump inlet size
✓ Avoid air pockets in suction line

Step 4: Pump Size Selection

Flow Range by Port Size

Optimal Operating Point

Optimal Point = 60-80% of maximum capacity

Why?
- At max capacity: High wear, short life
- Below 50%: Inefficient air consumption
- 60-80%: Best balance of life and performance

Selection Example

Requirements:
- Flow: 100 GPM
- Pressure: 50 psi

Option 1: 1" pump (max 100 GPM)
- Operating at 100% = Too high ❌

Option 2: 1-1/2" pump (max 150 GPM)
- Operating at 67% = Good ✓

Option 3: 2" pump (max 230 GPM)
- Operating at 43% = OK but inefficient

Best choice: 1-1/2" pump ✓

Step 5: Material Selection

Material Selection Matrix

Quick Material Reference

Housing Materials:

Diaphragm Materials:

Step 6: Air Supply Verification

Air Consumption Estimation

Quick Estimate:

SCFM ≈ GPM × 1.5 to 2.0 (at moderate pressures)

Typical Air Consumption by Size:

Air Supply Checklist

□ Available air pressure: ___ psi (need 10-20 psi above discharge)
□ Available air volume: ___ SCFM
□ Air quality (filtration, drying)
□ Distance from compressor
□ Pipe size adequate

Air Supply Requirements

Step 7: Accessories

Common Accessories

Pulsation Dampener Sizing

Dampener Volume ≥ 10 × Stroke Volume (for 90% reduction)

Example:
Stroke volume = 500 mL
Dampener volume = 500 × 10 = 5,000 mL = 5 L

Step 8: Final Verification

Selection Checklist

Performance:
□ Flow rate within 60-80% of max
□ Pressure within rating
□ Suction conditions acceptable
□ Air supply adequate

Materials:
□ Housing compatible with fluid
□ Diaphragm compatible with fluid
□ Elastomers compatible with fluid
□ Temperature rating adequate

System:
□ Pipe sizes match pump ports
□ Pulsation dampener sized (if needed)
□ Air supply piped correctly
□ Accessories specified

Decision Tree

When to Choose AODD

START
  │
  ▼
Need pump for transfer application?
  │
  ├── YES: Continue
  │
  ▼
Hazardous area (ATEX required)?
  │
  ├── YES → AODD (inherently safe) ✓
  │
  ▼
Self-priming required?
  │
  ├── YES → AODD excellent choice ✓
  │
  ▼
May run dry?
  │
  ├── YES → AODD (safe) ✓
  │
  ▼
Continuous precise flow needed?
  │
  ├── YES → Consider centrifugal or progressive cavity
  │
  ▼
Shear sensitive fluid?
  │
  ├── YES → AODD good choice ✓
  │
  ▼
High flow (>300 GPM)?
  │
  ├── YES → Consider other pump types
  │
  ▼
AODD is suitable choice ✓

AODD vs Other Pumps Quick Guide

Viscosity Correction

Flow Correction Factors

Viscosity Selection Adjustment

Corrected Flow = Catalog Flow × Viscosity Factor

Example:
Catalog flow at duty point: 100 GPM
Fluid viscosity: 2000 cP
Factor: 0.65
Actual flow: 100 × 0.65 = 65 GPM

Action: Select larger pump to compensate

Sizing Worksheet

=== AODD PUMP SIZING WORKSHEET ===

1. PROCESS REQUIREMENTS
Required flow: ___ LPM (___ GPM)
Design flow (+20%): ___ LPM
Discharge pressure: ___ bar (___ psi)
Suction lift: ___ m (___ ft)
Fluid: _______________
Temperature: ___ °C
Viscosity: ___ cP
Specific gravity: ___
Solids: ___ % / ___ mm size

2. PUMP SELECTION
Selected pump size: ___ inch
Max flow at duty pressure: ___ GPM
Operating percentage: ___ % (target 60-80%)
Selected model: _______________

3. MATERIALS
Housing: _______________
Diaphragm: _______________
Ball/Seat: _______________
O-rings: _______________

4. AIR SUPPLY
Required pressure: ___ psi
Required volume: ___ SCFM
Available pressure: ___ psi ✓
Available volume: ___ SCFM ✓

5. ACCESSORIES
□ Pulsation dampener: Size ___ L
□ Suction strainer: Size ___
□ FRL unit: Size ___
□ Muffler
□ Other: _______________

6. VERIFICATION
□ Flow at 60-80% capacity
□ Pressure within rating
□ Materials compatible
□ Air supply adequate
□ Accessories specified

Common Selection Mistakes

Mistakes to Avoid