Why Pulsation Analysis Is Critical for Rotating Equipment Reliability
High-frequency pressure pulsations and mechanical vibrations are often overlooked during piping design—yet they are a leading cause of fatigue failures, equipment downtime, and nozzle overloads. At iFluids Engineering, we offer specialized pulsation analysis and mechanical vibration for positive displacement pumps (PDPs) and reciprocating compressors (RCs) using the industry-leading Applied Flow Technology AFT Impulse software for hydraulic and acoustic simulations and CAESAR II for finite element-based static and dynamic stress analysis. Our service helps you identify hidden resonance risks, reduce dynamic stresses, and fully comply with global standards such as API 674, API 618, and ISO 10816.
API 674, in particular, defines minimum requirements for the design and construction of reciprocating PDPs, with extensive emphasis on pulsation and vibration control. It outlines criteria such as allowable nozzle forces/moments, mechanical design lifespan, materials, stress limitations, and pulsation suppression requirements. Our services align fully with the expectations of API 674, which details standard approaches to managing pulsation and vibration.
Whether you’re designing a new pump system or investigating excessive vibration in existing assets, our team provides actionable insight backed by simulation, diagnostics, and field validation.
What is API 674 Compliance, and Why is it Important?
API 674 is the global standard governing the design and operation of reciprocating positive displacement pumps. It outlines key requirements for vibration control, pressure pulsation suppression, nozzle loading, and mechanical integrity. Compliance ensures long-term reliability, minimizes fatigue failures, and helps facilities meet international safety and performance benchmarks.
Why do positive displacement pumps require pulsation analysis?
Positive displacement pumps generate cyclical pressure waves that can cause high-frequency pulsations. Without proper analysis, these pulsations can lead to pipe fatigue, nozzle damage, and even system resonance failures. Pulsation analysis ensures pressure waves are controlled using techniques like dampeners and orifice plates, aligned with API 674 guidelines.
How does vibration affect pump and piping systems?
Mechanical vibration can amplify stress on piping systems, loosen supports, and increase the risk of equipment misalignment or failure. By identifying vibration nodes and applying damping strategies, vibration assessment protects system integrity and extends asset lifespan.
Our Core Offerings
- Pulsation Analysis (Positive Displacement Pumps) – Positive Displacement Pumps (PDPs) produce non-uniform flow, creating cyclical pressure waves. In accordance with API 674, we:
- Conduct acoustic simulation using AFT Impulse to identify pressure wave nodes, anti-nodes, and potential amplification zones
- Analyze the system acceleration head, a key parameter in suction piping as defined in API 674
- Compare predicted pressure pulsation amplitudes to API 674 guidelines for acceptable levels
- Recommend the use of pulsation dampeners, orifice plates, or volume bottles for suppression
- Compressor Pulsation and Vibration Study – Reciprocating Compressors (RCs) introduce complex harmonics due to their cyclic nature. Our methodology includes:
- Manifold resonance assessment and baffle design evaluation per API 618
- Optimized design of volume bottles, choke tubes, and snubbers to control acoustic pressure waves
- Structural and acoustic separation of compressor components to reduce transmission of pulsation to piping
- Mechanical Vibration Analysis – Mechanical integrity is strongly linked to vibrational stability. We follow ISO 10816 / ISO 2372 to:
- Quantify casing vibration velocity (in mm/s RMS) and compare against severity limits for equipment class
- Simulate natural frequencies using CAESAR II to ensure spacing from running speed harmonics
- Apply modal damping strategies and mechanical fixes like supports and hold-downs to reduce dynamic amplification
- Nozzle Load and Support Optimization – Nozzles are critical interfaces between equipment and piping. Based on API 610, API 674 Section 6.6, and EIL 6501-7-12-0038, we:
- Model external forces and bending moments acting on equipment nozzles
- Compare forces to allowable limits
- Propose support designs that reduce reaction loads and dynamic amplification
- Validate the final design under static, operating, and transient load cases using CAESAR II
Our Process – From Data to Design Validation
- Data Gathering
We begin by reviewing site conditions, pump/compressor layouts, existing supports, and historical vibration or failure records. Process data (flow, pressure, temperature) and mechanical specs are collected. - System Modeling and Simulation
Using AFT Impulse, we model the hydraulic and acoustic behavior of the piping system. The simulation highlights pressure pulsation zones, transient surge effects, and resonance frequencies. - Vibration Evaluation
We identify critical vibration nodes by analyzing pipe spans, support stiffness, and modal behavior using CAESAR II. ISO 10816 thresholds are applied to evaluate vibration severity. - Stress and Load Analysis
Based on the simulation outcomes, we evaluate piping loads transferred to equipment nozzles and ensure compliance with API 610 / API 674 standards. The pipe support layout is reviewed for adequacy under dynamic loads. - Mitigation and Redesign Recommendations
Final reports include specific engineering recommendations such as pulsation dampeners, optimized support placements, baffle adjustments, or layout changes to mitigate pulsation and vibration. - Documentation and Handover
Deliverables include simulation models, vibration charts, support drawings, and a comprehensive report for compliance, execution, and audit purposes.
Industries We Support
| Sector | Applications |
| Oil & Gas Refineries | Wash water pumps, injection lines, compressor skids |
| Petrochemical Plants | Chemical feed pumps, reciprocating gas compressors |
| Power Plants | Boiler feed pumps, condensate extraction systems |
| Fertilizer & Process Industries | Ammonia loop pumps, urea pumps, synthesis gas lines |
| Pipeline Terminals | Wash water pumps, injection lines, and compressor skids |
Codes and Standards We Follow
- API 674 – Reciprocating Positive Displacement Pumps (PDPs) – Focus on vibration and pressure pulsation control
- API 618 – Reciprocating Compressors – Vibration and acoustic management criteria
- API 610 / API 617 – Centrifugal pumps and compressors – Nozzle load evaluation guidelines
- ISO 10816 / ISO 2372 – Classification of vibration severity on rotating machines
- ASME B31.3 – Process piping design and stress criteria
- DNV-RP-D101 – Dynamic response evaluation and resonance avoidance strategies
- Learn more about our Finite Element Analysis (FEA) Services
- Explore our detailed Pipe Stress Analysis Services
- View our complete Engineering Services
Partner With Us for Dynamic System Integrity
Pulsation and vibration failures often go unnoticed until they cause major damage. Let iFluids Engineering help you get ahead of these issues with precision modeling, field expertise, and engineering-backed recommendations.
“iFluids Engineering – Engineering Stability in Every Stroke“