Double Flange Steel Expansion Joint

The Double Flange Steel Expansion Joint (also known as VSSJA-2/B2F type) consists of body, sealing ring, gland, telescopic pipe, and limit nuts. The product incorporates a limit device on the basis of the loose expansion structure, locked with double nuts at the maximum expansion point. The pipe expands and contracts freely within the allowable range; once the limit is exceeded, rigid limitation engages.

Dafugui, located in Wenzhou, Zhejiang, is equipped with advanced CNC machining facilities and a strict quality control system. From raw material incoming to finished product dispatch, every process undergoes rigorous inspection. Materials can be selected from Carbon Steel Q235, Ductile Iron QT400-15, Stainless Steel 316, or Cast Steel based on operating conditions, ensuring excellent performance in various environments.

High-Strength Structure, Long-Lasting Durability

All-steel body and telescopic pipe design offer high tensile and compressive strength. Compared with rubber joints, steel expansion joints perform more stably under high-temperature, high-pressure, and corrosive media conditions, with a longer service life, particularly suitable for steam pipelines and industrial circulating water systems.

Precise Limiting, Safety Protection

Double-nut limit device precisely locks at the maximum expansion point. The joint operates freely during normal conditions, but once pipeline displacement exceeds the limit, rigid limitation immediately engages to prevent pull-out or damage, avoiding pipeline leakage and equipment failure caused by excessive displacement.

Technical Specifications

Installation Guide

1. Pre-installation: Loosen the gland bolts and extend the product to the installation length
2. Connect Flanges: Adjust the connection length between both ends and pipeline flanges, ensuring proper alignment
3. Tighten Bolts: Tighten gland bolts evenly and diagonally in sequence to prevent uneven compression
4. Adjust Limiting: Adjust limit nuts to the design position to lock the expansion amount
5. Overhead Installation: For overhead applications, appropriate fixed supports must be installed at both ends

FAQ

Q1: Are Double Flange Steel Expansion Joint and Double Flange Limited Expansion Joint the same product?

A: They are essentially the same category of product, both designed to compensate for pipeline displacement with limit protection. Different manufacturers may use different naming conventions. Dafugui's VSSJA-2 (B2F) model covers both. Just confirm that the standard, diameter, pressure, and material meet your operating conditions.

Q2: What is the difference between steel expansion joints and rubber joints? How to choose?

A: Steel expansion joints feature an all-metal structure with higher temperature resistance (up to 250℃) and higher pressure capacity (up to 2.5MPa), suitable for steam, high-temperature water, and corrosive media. Rubber joints offer better vibration damping and noise reduction, suitable for normal temperature and low pressure conditions. If your pipeline operates at higher temperatures or with corrosive media, steel expansion joints are recommended.

Q3: Does Dafugui support export? Which markets do you serve?

A: Yes. Dafugui is located in Wenzhou, Zhejiang. We have mature export packaging and logistics experience to ensure product safety during long-distance transportation.

Q4: Can non-standard sizes or special materials be customized?

A: Yes. Dafugui supports non-standard customization services, including non-standard diameters (beyond DN50-DN3000 range), special materials (e.g., full stainless steel 316L, duplex stainless steel), and special working pressures. Please provide your operating parameters and our technical team will develop a customized solution.