Power Plant Spring Support

In power plants, main steam pipelines, high-temperature reheat steam pipelines and other similar systems continuously transport media under high temperature and high pressure conditions, while undergoing thermal expansion ranging from several millimeters to tens of millimeters. Rigid fixation converts these displacements into additional thrust forces that are transmitted to boiler headers and turbine interfaces, increasing stress on weld joints, flanges and equipment casings.

This figure shows the load‑displacement performance curve of a variable spring support/hanger, including key parameters of load and displacement to verify the product’s load‑bearing accuracy and operational reliability.

Each unit is subject to load calibration and performance testing prior to shipment. The setting‑load deviation is controlled within ±5%, complying with ANSI/MSS‑SP‑58‑2018 international standard as well as NB/T47039‑2013.

Products meet technical requirements for power, petro‑chemical and other industrial piping systems. Per MSS‑SP‑58‑2018, the maximum allowable load variability for variable spring units shall not exceed 25% of operating hot‑load within full working travel.

Load‑displacement curve obtained from the type test of a constant spring support/hanger. The horizontal axis stands for displacement while the vertical axis represents load. The curve stays approximately horizontal across the full working travel, demonstrating that the supporting force remains essentially constant when piping deflects due to thermal expansion and contraction.

This type test verifies load constancy, full‑travel stability and operational reliability of constant spring units. All production units are subject to load calibration prior to shipment, with load deviation controlled within ±6% in accordance with ANSI/MSS‑SP‑58‑2018 and NB/T47038‑2013.

These products are applicable to industrial piping systems with large thermal displacement, including main‑steam pipelines and other high‑temperature & high‑pressure piping.

Developed specifically for these operating conditions by Yangzhou Tianshun Pipeline Technology Co., Ltd., the Power Plant Spring Support compensates for displacement through elastic loading, maintaining pipeline stress within standard allowable limits. This document explains the design philosophy, operational performance and engineering support approach of this product, based on the actual requirements of steam pipeline systems.

Requirements for Elastic Supports in Steam Pipeline Stress Control

Steam pipeline design generally follows codes such as ASME B31.1, which require pipe supports/hangers to bear both pipeline dead weight and media weight without impeding thermal displacement. If support force varies excessively with displacement, local piping system stress may exceed allowable values, forcing on-site adjustments or even rework.

Furthermore, turbine and boiler interfaces typically have very strict allowable limits for forces and moments. Improper support solutions can significantly shorten the service life of main equipment interfaces. This requires support/hanger products to provide stable and predictable support forces within the specified stroke, while offering sufficient adjustment margin to accommodate on-site deviations.

How Power Plant Spring Supports Address These Requirements

Power Plant Spring Supports are available in two configurations: variable spring and constant force spring, selected based on pipeline stress analysis results. Variable spring units carry load with linear stiffness, while constant force units utilize a primary and secondary spring mechanism to control support force variation rate within 5% throughout the entire working stroke, providing nearly constant support to the piping system from cold state to hot state.

Spring elements are manufactured from alloy spring steels including 60Si2Mn and 50CrVA. Structural components can be fabricated from carbon steel, heat-resistant steel or stainless steel. The overall temperature application range covers -196°C to +650°C, matching all thermal states of steam pipelines from low-temperature warm-up to full-load operation.

Every Power Plant Spring Support undergoes full-stroke compression testing with stiffness curve recording prior to shipment. The housing is equipped with a load-displacement nameplate and installation locking device. On-site installation only requires cold-state mounting; simply remove the locking pin after pipeline temperature rises, and the support/hanger enters operational state without on-site welding or complex adjustments.

On-Site Installation and Long-Term Operational Performance

Cumulative errors in foundation elevation and pipe section cutting are inevitable during steam pipeline installation. The height fine-tuning range provided by Power Plant Spring Supports absorbs these deviations, preventing rigid binding. Constant force spring units are typically equipped with screw or hydraulic auxiliary adjustment mechanisms, enabling single-person operation even on large-diameter heavy-duty pipelines.

During long-term operation, the anti-relaxation spring design and surface treatments (hot-dip galvanizing or Dacromet coating) maintain stable support performance. In multiple overseas power plant projects, over 70% of subsequent support/hanger orders come from existing customers. This high repeat purchase rate indirectly validates the long-term performance of our products.

Typical Installation Locations and Functions

In the boiler area, Power Plant Spring Supports are installed on vertical and horizontal sections of main steam ducts, superheater outlet pipelines and reheat steam pipelines. They absorb upward thermal expansion, preventing excessive stress at header nozzle connections.

Near the turbine, spring supports/hangers on high-temperature steam pipeline sections close to main steam valves and governing valves reduce component forces and moments, helping maintain shaft alignment. Although feedwater and attemperation water pipelines operate at lower temperatures, they still experience significant start-stop temperature differences. Elastic supports maintain pipeline slope and reduce cavitation risk.

In these applications, supports/hangers are often combined with dampers, limit brackets and other components to form a complete piping system flexible restraint solution.

Project Technical Support and Product Acceptance

Starting from the selection phase, our technical team receives piping system stress analysis reports, calculates the design load and displacement for each support point, recommends appropriate Power Plant Spring Support types and spring constants, and provides detailed installation guidance.

Our factory maintains a complete quality control chain from spring wire incoming re-inspection, hardness testing after heat treatment to finished product stiffness testing. Relevant process records and material quality documents can be delivered in accordance with standards such as ASME and CE. For nuclear power conventional islands and other high-requirement projects, additional support function qualification test reports and traceability documents can be provided.

If you have steam pipeline support requirements, please provide piping layout drawings and stress data. We will deliver a specific Power Plant Spring Support configuration solution rather than a generic model list. Leveraging Yangzhou Tianshun's 14 years of pipeline supporting experience and project data from 45 countries worldwide, we can help you control overall procurement and installation costs while ensuring the safety of your steam system.

All products undergo comprehensive in-house testing prior to shipment.

In-house testing includes: dimensional and visual inspection, PMI (Positive Material Identification), hardness testing, MT/PT non-destructive testing (where applicable), spring load testing (with load-displacement curves), and coating thickness measurement.

Factory Test Reports (FTR) and Material Test Reports (MTR) are provided.

In-house testing does not constitute third-party testing accredited by ILAC. Third-party witnessed testing or laboratory testing is available as a separate, optional service.

Optional third-party inspection services (quoted separately):

1. Material testing: chemical composition analysis, tensile testing, Charpy low-temperature impact testing, and hardness testing.

2. Weld NDT: Magnetic Particle Testing (MT), Liquid Penetrant Testing (PT), Ultrasonic Testing (UT), and Radiographic Testing (RT).

3. Spring load performance testing, including load-displacement curves.

4. Hot-dip galvanizing/epoxy coating corrosion protection inspection.

5. Witnessed testing, factory surveillance, and Pre-Shipment Inspection (PSI).

Our product load accuracy, testing standards, and documentation systems are benchmarked against the LISEGA international pipe support system. Unlike standard domestic manufacturers that supply only the product itself, we provide a load-displacement curve with every spring unit; we also facilitate third-party SGS testing and witnessed inspections, and support document reviews by PE/CPE engineers for overseas projects.