AODD Pump Wetted Parts and Ball Materials Guide

Wetted Parts Overview

What Are Wetted Parts?

Wetted parts are all components that contact the process fluid:

┌─────────────────────────────────────┐
│         AODD PUMP WETTED PARTS      │
│                                     │
│   ┌─────────────────────────────┐   │
│   │    HOUSING (body)           │   │
│   │    ┌─────────────────────┐  │   │
│   │    │   DIAPHRAGM         │  │   │
│   │    └─────────────────────┘  │   │
│   │    ┌─────────────────────┐  │   │
│   │    │   BALL (check)      │  │   │
│   │    │   SEAT              │  │   │
│   │    └─────────────────────┘  │   │
│   │    ┌─────────────────────┐  │   │
│   │    │   O-RINGS           │  │   │
│   │    │   GASKETS           │  │   │
│   │    └─────────────────────┘  │   │
│   │    ┌─────────────────────┐  │   │
│   │    │   MANIFOLDS         │  │   │
│   │    └─────────────────────┘  │   │
│   └─────────────────────────────┘   │
└─────────────────────────────────────┘

Material Selection Importance

Housing Materials

Polypropylene (PP)

Chemical Resistance: ★★★★☆
Temperature:         ★★★☆☆ (up to 80°C)
Pressure:           ★★★☆☆ (up to 100 psi)
Cost:               ★☆☆☆☆ (Low)

Compatible with:

• Dilute and concentrated acids
• Bases
• Alcohols
• Water-based fluids

Not compatible with:

• Chlorinated solvents
• Strong oxidizers
• Aromatic hydrocarbons

Best for:

• Chemical transfer
• Water treatment
• Low-cost applications

PVDF (Kynar)

Chemical Resistance: ★★★★★
Temperature:         ★★★★☆ (up to 120°C)
Pressure:           ★★★☆☆ (up to 100 psi)
Cost:               ★★★★☆ (High)

Compatible with:

• Concentrated acids
• Strong bases
• Chlorinated solvents
• Most aggressive chemicals

Not compatible with:

• Very few chemicals
• Strong oxidizers at high concentration

Best for:

• Aggressive chemical service
• High purity applications
• Semiconductor

Aluminum

Chemical Resistance: ★★☆☆☆
Temperature:         ★★★★☆ (up to 120°C)
Pressure:           ★★★★☆ (up to 125+ psi)
Cost:               ★☆☆☆☆ (Low)

Compatible with:

• Water
• Non-aggressive slurries
• Some petroleum products

Not compatible with:

• Acids
• Strong bases
• HALOGENATED HYDROCARBONS ⚠️

⚠️ CRITICAL WARNING: Never use aluminum with chlorinated hydrocarbons (Carbon Tetrachloride, Methylene Chloride, Chloroform, Trichlorethylene). Explosion risk!

Best for:

• General purpose
• Abrasive slurries (non-chemical)
• Dewatering

316 Stainless Steel

Chemical Resistance: ★★★★☆
Temperature:         ★★★★★ (up to 175°C)
Pressure:           ★★★★★ (up to 125+ psi)
Cost:               ★★★★☆ (High)

Compatible with:

• Most solvents
• Many acids (phosphoric, sulfuric <10%)
• Food applications

Not compatible with:

• Hydrochloric acid
• High chloride concentration (>500 ppm at elevated temp)
• Pitting environments

Best for:

• Food and beverage
• Pharmaceutical
• High-pressure applications
• Sanitary service

Cast Iron

Chemical Resistance: ★★☆☆☆
Temperature:         ★★★★★ (up to 343°C)
Pressure:           ★★★★★ (High)
Cost:               ★☆☆☆☆ (Low)

Compatible with:

• Clean water (pH 6-10)
• HVAC systems
• Non-corrosive fluids

Not compatible with:

• Acids
• High chloride water
• Corrosive chemicals

Best for:

• Water systems
• HVAC
• Industrial general service

Housing Material Comparison

Ball Check Valve Materials

Ball Material Selection

Ball material must match:

1. Chemical compatibility
2. Fluid viscosity (density affects seating)
3. Solids handling

Common Ball Materials

Ball Selection by Application

Ball Weight Importance

Viscosity vs Ball Density:

Low Viscosity (<100 cP):
  ○ Light balls (EPDM, Santoprene) work fine

High Viscosity (>1000 cP):
  ● Heavy balls (PTFE, SS) needed
  - Light balls may not seat properly
  - Check valve fails to close fully

Seat Materials

Seat Importance

The seat provides the sealing surface for the ball check valve:

┌─────────────┐
│             │
│    ○        │ ← Ball
│   ╱╲╱╲      │ ← Seat (sealing surface)
│             │
└─────────────┘

Common Seat Materials

Ball/Seat Combinations

O-Ring and Gasket Materials

O-Ring Selection

O-rings seal static joints in the pump:

O-Ring Matching

Rule: O-rings should match or exceed diaphragm compatibility

Example:
- Diaphragm: PTFE
- O-rings: PTFE or Viton (not Buna-N!)

Complete Wetted Parts Specification

Specification by Service

Chemical Service (Acids/Bases):

Housing:    PVDF or PP
Diaphragm:  PTFE (backed)
Ball:       PTFE
Seat:       PTFE
O-rings:    PTFE or Viton

Petroleum Service:

Housing:    Aluminum or SS
Diaphragm:  Buna-N or Viton
Ball:       Buna-N
Seat:       Buna-N
O-rings:    Buna-N or Viton

Food/Pharma Service:

Housing:    316 SS (electropolished)
Diaphragm:  FDA PTFE
Ball:       PTFE or SS
Seat:       PTFE or SS
O-rings:    FDA EPDM or PTFE

General Water Service:

Housing:    PP or Aluminum
Diaphragm:  EPDM or Santoprene
Ball:       EPDM or Santoprene
Seat:       EPDM or Santoprene
O-rings:    EPDM

Abrasive Slurry Service:

Housing:    SS or PVDF
Diaphragm:  Santoprene
Ball:       316 SS
Seat:       316 SS
O-rings:    EPDM or Viton

Material Selection Matrix

Quick Reference by Fluid

Specification Template

=== AODD PUMP WETTED PARTS SPECIFICATION ===

Service: _______________
Fluid: _______________
Temperature: ___ °C
Pressure: ___ bar

HOUSING:
Material: □ PP □ PVDF □ AL □ SS □ CI
Justification: _______________

DIAPHRAGM:
Material: □ PTFE □ EPDM □ Santoprene □ Buna-N □ Viton
Backed: □ Yes □ No
FDA: □ Required □ Not required

BALL:
Material: □ PTFE □ SS □ EPDM □ Buna-N □ Santoprene
Heavy ball for viscous: □ Yes □ No

SEAT:
Material: □ Same as ball □ Different: ___

O-RINGS:
Material: _______________
FDA: □ Required □ Not required

VERIFICATION:
□ All materials compatible with fluid
□ All materials rated for temperature
□ FDA/regulatory compliance checked
□ ATEX requirements met (if applicable)

Common Material Mistakes