Precision Constant Spring Hanger For Large-Displacement Pipeline With Uniform Load Output

Constant spring hangers, also referred to as constant load spring supports or constant force supports, deliver a near-uniform supporting force throughout the full travel range of the pipe. These units are specifically engineered for piping systems that experience significant vertical thermal displacement, where variable spring supports would introduce excessive load variation and transfer unwanted stress to connected equipment and pipework.

At Yangzhou Tianshun Pipeline Technology, we manufacture constant spring hangers using a proven crank-connecting rod mechanism paired with high-quality compression springs. This design balances spring torque against load torque around the main axis throughout the entire stroke, maintaining load deviation within ±5% as standard — and ±3% for high-precision configurations. Each assembly is housed in a protective casing that shields internal components from construction debris and environmental contaminants, reducing maintenance risk over the service life of the support.

Technical Specifications & Series

Our constant spring support portfolio covers a working load range from 0.1 kN to 500 kN, with standard travel options of 50 mm, 100 mm, 200 mm, and 400 mm, and custom travels available up to 600 mm. Standard series include PH, LH, CA, CS, and TH models, suitable for both horizontal and vertical installation. Spring coils are manufactured from 60Si2Mn or 50CrVA alloy steel, and housings are finished in hot-dip galvanized or epoxy coating to suit ambient operating temperatures from -20°C to +80°C.

Every constant spring hanger is factory-preset to the customer's specified load and cold/hot positions, and fitted with upper and lower travel limit stops to prevent over-travel. A clearly visible travel scale and load adjustment dial allow for on-site fine-tuning within ±10% of the rated load, with some configurations adjustable up to ±20% in 2% increments. Red preset pins are installed at the factory to lock the support during hydrostatic testing and acid washing, withstanding up to twice the rated load before removal at system commissioning.

Standards & Custom Engineering

All constant load spring supports are designed and manufactured in compliance with GB/T 17116.1/.2/.3 and NB/T 47039, and are fully convertible to international standards including MSS SP-58, ASME B31.1 / B31.3, EN 13480-3, VGB-R 510 L, and JIS B 8501. As an experienced pipe supports manufacturer, we also produce fully custom constant force supports based on customer drawings and project-specific parameters.

Application Across Critical Industries

Constant spring hangers are specified in piping systems where load consistency is non-negotiable. Typical installations include thermal power plants, nuclear power facilities, refineries, LNG and LPG terminals, district heating networks, and high-temperature process lines in petrochemical and pharmaceutical plants. They are often deployed alongside variable spring supports on the same pipeline — constant units at high-displacement nodes and variable spring hangers at locations with smaller thermal movement.

Broader Pipe Support Product Range

Beyond constant spring hangers, our complete pipe support portfolio includes variable spring supports, rigid hangers, pipe shoe supports, pre-insulated pipe supports, and hydraulic snubbers for dynamic load control. For projects requiring thermal movement compensation, we also supply metal bellows expansion joints, rubber expansion joints, and fabric expansion joints that integrate with our support systems to form a complete pipeline solution.

Quality & Service Assurance

Every support undergoes full in-house testing before shipment, backed by our ISO 9001:2015 quality management system and compliance with ASME and API standards where required. Clients receive dedicated technical support from inquiry through installation, 24-hour response on all quotations, and on-site load adjustment guidance as part of our after-sales service. With over 14 years of manufacturing pipe supports and expansion joints for projects across 45 countries, we supply both standard catalog units and fully engineered custom solutions for EPC contractors and end-users worldwide.

Frequently Asked Questions

What is the difference between a constant spring hanger and a variable spring support?

Variable spring supports exert a varying reaction force as the pipe moves vertically, due to spring compression or extension. Constant spring hangers use a crank-connecting rod mechanism to maintain a nearly uniform supporting force throughout the full travel range. As a rule of thumb, constant units are specified where thermal displacement exceeds 50 mm or where load variation must stay below 6% to avoid transferring stress to pumps, turbines, or other sensitive equipment.

What does ±5% load deviation mean on a constant spring support?

Load deviation is the maximum percentage difference between the actual supporting force and the nominal rated load at any point within the working travel. Our standard constant spring hangers hold deviation within ±5%, which meets most industrial piping requirements. For critical applications such as nuclear or high-precision process lines, we offer high-precision units at ±3% deviation.

When should the red preset pins be removed?

The preset pins are factory-installed to lock the hanger at its cold-installation position, allowing hydrostatic testing and pipe acid-washing to be completed without compressing or extending the spring assembly. They must be removed before the system is put into operation, typically after hydrotesting and pre-commissioning checks are finished. Our standard pins withstand up to twice the rated load during testing; let us know if your project requires a higher safety margin.

Can the load be adjusted on site after installation?

Yes. Each constant spring hanger is fitted with a load-adjusting screw and a calibrated dial. Turning the screw increases or decreases the preset load in 2% increments, with a total adjustment range of ±10% on standard units (up to ±20% on selected configurations). This allows fine-tuning to compensate for minor differences between design conditions and actual site installation.

Which standards do your constant spring hangers follow?

Our standard range is designed to GB/T 17116.1/.2/.3 and NB/T 47039, and is dimensionally and performance-convertible with MSS SP-58, ASME B31.1, ASME B31.3, EN 13480-3, VGB-R 510 L, and JIS B 8501. We can also manufacture fully custom supports to your project drawings and specifications.

What is the typical lead time?

Standard catalog constant spring hangers generally ship within 15 to 25 working days, depending on quantity and series. Custom-engineered units require additional engineering and confirmation time. Rush delivery can be arranged on request, subject to prior agreement at order placement or at least 20 days before the scheduled delivery date.