Reference profile
- Designation
- ASME PTC 10
- Title
- Performance Test Code on Compressors and Exhausters
- Issuing body
- American Society of Mechanical Engineers (ASME)
- Current edition
- ASME PTC 10-1997 (Reaffirmed 2014)
- Status
- Active; international benchmark code for thermodynamic performance testing of axial and centrifugal compressors.
- Category
- Compressor Performance Test Code Standard
1
Overview
ASME PTC 10 provides standard test procedures to determine the thermodynamic performance of axial and centrifugal compressors under specified operational gas conditions.
It defines methodologies to accurately measure mass/volume flow rates, pressure ratios, polytropic/isentropic head, polytropic efficiency, and gas power consumption, accounting for real gas behavior (Schultz method) and dynamic similarity laws for factory substitute gas testing.
2
Scope & Applicability
Covers
- Test Classifications: Type 1 Test (tested under specified operational gas, pressure, and temperature conditions) and Type 2 Test (tested with substitute test gas under dynamic similarity rules).
- Dynamic Similarity Criteria: Rules for controlling non-dimensional parameters—Machine Mach Number (Mm), Machine Reynolds Number (Rem), Capacity-Speed Ratio (q1/N), and Volume Ratio (v1/v2).
- Real Gas Thermodynamics: Polytropic work and efficiency calculation methods for real gases using Schultz Method or Lee-Kesler / Redlich-Kwong equations of state.
- Instrumentation & Measurements: Precision static pressure taps, calibrated RTDs/thermocouples, and ASME flow nozzles/orifices (ASME MFC-3M).
- Test Conversion & Guarantee Comparison: Procedures to convert raw test data to specified site operating conditions for contractual guarantee compliance.
Does NOT cover (exclusions)
- Positive displacement compressors (reciprocating or rotary screw)—covered by ASME PTC 9 or ISO 1217.
- Low-pressure industrial fans and blowers—refer to ASME PTC 11 or AMCA 210.
- Mechanical vibration and rotor dynamic evaluations—covered by API 617.
- Driver performance testing (steam turbines, gas turbines, electric motors)—refer to ASME PTC 6 or PTC 22.
3
Key Requirements
Type 1 vs Type 2 Test Mandates
- Type 1 Test: Conducted when the specified process gas (or safe equivalent like Air/N2) can be used within tight operational tolerance limits (deviations in gas properties, speed, and inlet pressure < ±5%).
- Type 2 Test: Mandated when specified gas is toxic, flammable, or beyond shop facility limits. A substitute gas (e.g. N2, CO2, R-134a) is used under strict dynamic similarity control.
Dynamic Similarity Permissible Deviations (Type 2 Test)
- Capacity-Speed Ratio (q1/N): Permissible deviation between test and specified conditions must be within ±2% to ±4%.
- Machine Mach Number (Mm): Test Mach number deviation must not exceed ±2% (for Mm > 0.8) or ±5% (for Mm < 0.8).
- Machine Reynolds Number (Rem): Rem ratio should be kept within limits; Reynolds Number Correction Factor per PTC 10 must be applied if Rem differs.
Real Gas Thermodynamics & Schultz Method
- Schultz Method Mandate: For real gases deviating from ideal gas laws, Polytropic Head (Hp) and Polytropic Efficiency (ηp) must be calculated using the Schultz Real Gas Method.
- Compressibility Factor (Z): Compressibility factors Z1 (inlet) and Z2 (discharge) must be derived using certified equations of state (Lee-Kesler or Redlich-Kwong).
Instrumentation Precision & Thermal Equilibrium
- Calibrated Instrumentation: Pressure transmitters, RTDs, and flow orifices must be calibrated prior to testing with traceable standards.
- Thermodynamic Steady State: The compressor must operate continuously at each test point until oil temperatures, casing thermal expansion, and gas conditions stabilize (steady state for ≥ 30 mins).
4
Technical Details
Polytropic Head (Hp) Schultz Formula: Hp = f * Z1 * R * T1 * (n / (n - 1)) * [(P2 / P1)^((n - 1) / n) - 1], where f is Polytropic head correction factor and n is polytropic exponent.
Gas Shaft Power Formula: P_shaft = (mass_flow * Hp) / ηp + Mechanical_Losses (bearing and seal losses).
Machine Mach Number Definition: Mm = U / a1, where U is impeller tip speed (m/s) and a1 is acoustic velocity at inlet conditions (m/s).
Where to find it in the codeConsult ASME PTC 10 Section 3 for Test Types & Permissible Deviations, Section 4 for Measurement Instruments & Piping Layouts, Section 5 for Schultz Real Gas Calculations & Conversion Formulas, Section 6 for Report Formats.
5
Engineering Notes
- When selecting a substitute gas for Type 2 testing (e.g. R-134a or Dry Air), verify that the specific heat ratio k = Cp/Cv and pressure/temperature profiles do not cause condensation (liquid droplet formation) inside impeller passages during testing.
- Ensure straight pipe runs upstream of flow measurement nozzles meet ASME MFC-3M requirements (minimum 20D to 30D straight run or flow straightener installation) to prevent swirl distortion in capacity readings.
- Always account for mechanical bearing and seal friction losses separately when deriving true gas thermodynamic efficiency from measured driver input power.
6
Related Standards
7
Source, Edition & Status
- Publisher
- ASME
- Edition Year
- N/A
- Industries
- Petrochemical, Refinery, Oil & Gas, Power, General Industry
- Content Status
- published
- Last Reviewed
- 2026-07-01
- Last Updated
- 2026-07-01
- Verified By
- Engineering Reviewer
- Official Link
- www.asme.org
This paraphrased summary is a discovery aid. Do not reproduce or substitute it for the copyrighted official publication or jurisdictional requirements.