When engineering systems for extreme low-temperature applications, managing thermal contraction and heavy structural loads is critical. In trunnion support piping, a specialized trunnion support is often welded directly to the piping, such as at a base elbow (ell), to provide a robust anchor or resting point.

Unlike standard pipe shoes, trunnions offer exceptional structural stability by distributing the load across a larger, reinforced surface area of the pipe wall. This design reduces localized stress and improves overall system reliability, particularly in high-load applications.

For cryogenic and low-temperature service, trunnion supports must be properly insulated using high-density polyurethane or similar materials. This insulation is essential to prevent thermal bridging, minimize moisture ingress, and avoid ice formation, all of which can compromise system performance and integrity.

Whether used as a static support or integrated with alignment devices such as a trunnion positioner, custom-engineered trunnion assemblies provide a reliable solution for maintaining structural integrity and safe operation in demanding industrial environments.

What is a Trunnion Pipe Support?

A trunnion pipe support is a structural component used to support a piping system and is connected directly to the process line. It functions as a secondary pipe element, helping hold the main line in position for stability. ASME standards guide their application and analysis to ensure safety and reliability, particularly in high-energy piping and under various operating conditions. 

In standard applications, trunnions are used to:

• Support sections of pipe vulnerable to weight or stress
• Help manage pressure at directional changes like elbows
• Provides added stability and structural strength by helping reinforce the system at critical load points
• Prevent displacement under heavy loads or external forces

In cryogenic systems, however, added challenges emerge. Maintaining thermal insulation at support points is critical. Without it, heat transfer through the support could lead to the evaporation of liquids into gases, cause condensation, and/or result in ice buildup. Over time, this can damage the pipe or disrupt flow.

Custom Trunnion Base ELL Pipe Supports for Cryogenic LNG Applications

At an LNG gasification facility, our customer required pipe supports that could prevent the transfer of heat and provide trunnion-like stability and strength. Piping Technology & Products collaborated closely with the client to design a customized solution that met both mechanical and thermal performance requirements.

The result was a trunnion base ELL support with a layered construction: an A36 carbon steel base, an integrated insulation block, and a stainless steel pipe saddle. This configuration prevented heat transfer between the pipe and the support.

By incorporating an insulation block into this design, we prevented heat transfer from the trunnion pipe support to the process line, which is a feature that a standard trunnion does not offer. The trunnion keeps the cold pipe separated from warmer support steel, suppressing frost build-up at the base and pipe rack. The pre-insulated support design maintained a steady temperature for the LNG from Point A to Point B, preventing it from warming up and converting from a liquid into a gas.

What Is a Trunnion Base ELL Support and How Does It Work? 

A trunnion base ELL support for LNG applications is a specialized insulated pipe support designed for cold-service and cryogenic process lines. It supports the main pipe while creating a thermal break between the pipe and the support base.

Unlike standard trunnions, which are not designed to address thermal integrity, this design minimizes thermal bridging. 

It typically uses:

• A carbon steel base for structural strength
• A block insulation layer to isolate temperature
• A stainless steel pipe saddle that connects to the process pipe

Where Trunnion Base ELL Supports Are Used

Trunnion base ELL supports are specifically designed for cold-service environments where thermal performance is critical. 

They are commonly used in LNG liquefaction and gasification facilities, where maintaining sub-zero temperatures is essential to system operations and safety. These supports also play a key role in ethylene and ammonia plants, which use chilled piping to move process materials while minimizing energy loss. 

In all cases, the design enables operators to move product from one stage to the next without experiencing temperature changes, condensation, or structural complications caused by frost buildup.

Key Field Benefits

• Thermal isolation is built in; it prevents cold pipe surfaces from transferring extreme temperatures to structural steel, helping maintain safe operating loads without added field insulation.
• Reduces condensation, prevents ice formation, and pipe damage
• Custom-fit to specification for pipe sizes ranging from 2 in. to 60 in., fitting cleanly into the line
• Supports heavy vertical loads while preserving pipe wall integrity
• Material matched to the parent pipe  to maintain mechanical and chemical compatibility
• Delivered fast, often within weeks, even for custom builds
• Provides rigid support in low-movement areas, preventing pipe sag or collapse in static runs or where line displacement is minimal.
• Helps reduce stress at elbows and vertical transitions, reinforcing piping in high-pressure or structurally sensitive locations.

Why Engineers Choose Trunnion Base ELL Supports

Engineers specify trunnion base ELL supports when thermal isolation is non-negotiable. These supports are sized according to the process pipe’s outside diameter and insulation thickness, ensuring a proper interface without modifying the pipe’s thermal envelope. 

The materials used, including carbon steel (for areas not in direct contact with the process line), high-performance insulation, and stainless steel, are known to perform reliably in environments that reach as low as -300°F.

Why Project Managers Trust It

Project managers rely on trunnion base ELL supports to avoid the common pitfalls that delay cold-service projects. Because the insulation is integrated into the support design, there’s no need to coordinate separate insulation crews or handle last-minute RFIs about support height or fit-up. 

Eliminating this extra field work speeds up installation, lowers labor coordination complexity, and reduces the risk of frost-related damage during startup. By arriving job-ready and material-matched, these supports enable faster handoff to commissioning teams and help keep the schedule on track.

Related Products Commonly Purchased

• Insulated pipe shoes
• Guides and stops
• Spring hangers (variable and constant)
• Pipe shoes
• Sway struts
• Sway braces
• Hydraulic and mechanical snubbers

Why Choose Piping Technology for Your Cryogenic Pipe Supports

We deliver custom-engineered cryogenic pipe supports built to meet the exact demands of cold-service environments. 

Our in-house team manages the entire fabrication process, from material selection to final delivery, providing you with tighter control over schedule and quality. 

For complex or high-load applications, we can perform Finite Element Analysis (FEA) to verify stress points and optimize steel thickness for performance and safety. With decades of experience and a proven track record in LNG, ammonia, and ethylene systems, we provide both the technical expertise and manufacturing speed your project requires.

Speak with an Engineer about trunnion support specifications or Request a Quote for your next cryogenic line.

FAQs

Q: Exactly what is a trunnion in the context of pipe supports? 

A: In industrial piping, a trunnion support is a cylindrical projection—typically a secondary section of pipe welded directly to the main pipe or elbow—that serves as a structural attachment point or resting base for a support. It provides a stable interface for transferring loads from the piping system to the supporting structure.

Q: How does a trunnion pin function within an industrial assembly? 

A: A trunnion pin acts as a central pivot point or load-bearing axle within an assembly, allowing connected components to rotate or accommodate movement. This helps reduce stress on the system while maintaining structural stability and proper alignment during operation.

Q: Are trunnion bearings required for all trunnion installations? 

A: Not always. For static support applications, trunnions may simply rest on a steel base or slide plate. However, in dynamic applications, trunnion bearings or specialized bearing-trunnion designs may be used to reduce friction and allow for smooth rotational or lateral movement during thermal expansion and contraction cycles.

Q: How is a trunnion bolt used in these support systems? 

A: A trunnion bolt is a heavy-duty fastener used to securely anchor the support assembly or its structural housing to the surrounding steel framework, ensuring the piping remains locked in its designated position under massive operational loads.

Q: Does the concept of a trunnion apply to pipeline valves as well, such as a trunnion valve ball?

 A: Yes. In a trunnion valve ball design, the internal ball is supported by top and bottom trunnions (shafts), which anchor it in place. This design absorbs line pressure and significantly reduces the operating torque required to open and close the valve compared to a standard floating ball valve, improving performance and reliability in high-pressure applications.