What does the filter separator calculator size?

It sizes coalescing filter separators for fuel gas conditioning and custody transfer, including two-stage element sizing, pressure drop, and efficiency calculations.

What standards does this calculator follow?

Calculations follow GPSA Sec 7 and ASME VIII standards for coalescing filter separator design.

Filter Separator Calculator | Coalescing Element Sizing

Service Conditions

Service Type Determines element type and efficiency requirements

Gas Flow Rate

At standard conditions (60°F, 14.7 psia)

Operating Pressure

psig

Operating Temperature

°F

Gas Properties

Gas Specific Gravity

Air=1.0

Natural gas: 0.55-0.80 typical

Gas Viscosity

At operating temperature

Compressibility Factor (Z)

Leave blank to estimate

Inlet Liquid Loading

gal/MMSCF

Typical: 0.5-5 gal/MMSCF

Gas Density Override (optional)

lb/ft³

Overrides SG-derived density. Mismatch >25% triggers warning.

Design Parameters

Element Type Affects capacity and efficiency

Efficiency Target

Max Pressure Drop (Clean)

psi

Typically 1-3 psi when new

Max Pressure Drop (Dirty)

psi

Element changeout threshold: 5-15 psi

Design Margin

Safety factor on element count

Override K-factor (optional)

ft/s

Second-stage Souders-Brown K. Default 0.15 (conservative). Typical 0.10–0.25.

📚 Learn the Theory

Understand coalescing filter design, element sizing, two-stage separation, and efficiency calculations

Read Engineering Guide →

Filter Separator Design

Element Capacity:

Q_element = A_face × V_face

Face velocity typically 40-80 ft/min for coalescing elements

Pressure Drop (Clean):

ΔP = K × (ρ × V²) / 2g_c

Typical Element Capacities (ACFM/element):
• 6" × 36" Fiberglass: 80-120 ACFM
• 6" × 48" Fiberglass: 100-150 ACFM
• Pleated cartridge: 150-300 ACFM

Service Requirements:
• Fuel gas: ≤0.1 gal/MMSCF outlet
• Instrument gas: ≤0.01 gal/MMSCF outlet
• Custody transfer: Per contract spec

Sizing Results

Vessel Size

Vessel Diameter: -

Vessel Length: -

Shell Thickness: -

First Stage (Coalescing)

Element Count: -

Element Size: -

Face Velocity: -

Second Stage (Separator)

Separator Type: -

Velocity Check: -

Performance

ΔP Clean: -

ΔP @ Changeout: -

Outlet Quality: -

Efficiency: -

Vessel Schematic

Reference Drawing

Filter Separator General Arrangement Drawing

Nozzle designations correspond to nozzle schedule

Filter Separator Calculator

Service Conditions

Gas Properties

Design Parameters

📚 Learn the Theory

Filter Separator Design

Sizing Results

First Stage (Coalescing)

Second Stage (Separator)

Performance

Vessel Schematic

Reference Drawing

Frequently Asked Questions

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