Pulsation and Mechanical Analysis

Pulsation (acoustical) and mechanical analysis of reciprocating compressor packages is the core business of ZCPPE. The purpose of pulsation and mechanical analysis is to reduce gas pressure pulsation in the piping system, thereby avoiding compressor operation complications regarding vibration, performance, reliability, flow measurement error, etc.

Due to the intermittent compressor suction and discharge, gas pressure pulsation in reciprocating compressor piping system is unstable. As a result, compressor operation problems can arise, namely unacceptable shaking force and piping vibration, system power consumption and energy loss, intake and discharge valves damage and flow measurement errors, etc.

API 618 (5th edition, December 2007), published by the American Petroleum Institute, presents three design approaches for pulsation and mechanical analysis. These approaches, namely design approach 1 (DA1), approach 2 (DA2) and approach 3 (DA3), are used for different cases, as detailed in the table below:


bentley table


Bentley Puls XM is one of the most authoritative software worldwide for pulsation (acoustical) analysis per API 618 design approaches. It was initially developed by NOVA-HUSKY research institute in Calgary, Canada, and then improved upon by the SSD engineering consulting firm, Bentley and other companies. It is currently an effective acoustical study tool.

 pressure pulsation

Pressure Pulsation Results of Stage 1 Suction System Model


Mechanical analysis is an important part of Design Approach 3 (DA3) in API 618.  The purpose of mechanical analysis is to adjust the piping layout and support design to avoid mechanical resonance of compressor manifold and piping systems, and thus limiting the vibration level and dynamic stress of compressor package components within the allowable range.

Bentley AutoPipe V8i is currently one of the most authoritative software worldwide for mechanical study. It can be used for analyzing piping system vibration and dynamic stress. Additionally, it also has a user-friendly interface with Bentley Puls XM for model data exchange.

ZCPPE uses Bentley Puls XM and Bentley AutoPipe V8i softwares to perform acoustical and mechanical studies of reciprocating compressor package as per API 618 design approaches.


compressor package

Dynamic Displacement Response of a Compressor Package System Subject to Unbalanced Shaking Forces and Cylinder Gas Pressure