Summary: We recently manufactured and delivered custom Notched Flange Adaptors for a Hong Kong-based industrial piping contractor. Made entirely of SS316L stainless steel, this batch covered sizes DN200, DN300, DN400, and DN900. Designed around real installation challenges, these notched adaptors specifically address the difficulties of retrofitting aging infrastructure where pipes cannot be rotated and space is highly restricted.

Order Overview

This project involved the production of large-diameter AF flange adaptors with a specific design modification: notched flanges. The sizes covered DN200, DN300, DN400, and DN900.

The customer, an experienced contractor in Hong Kong, required full SS316L construction to withstand highly corrosive environments. More importantly, they needed the adaptors designed to overcome severe on-site installation constraints, providing a practical solution for retrofitting existing piping systems without the need for extensive fabrication or system shutdowns.

Design Advantages: Why Notched Flange Adaptors?

Standard flange assemblies often fail to fit the reality of job sites—especially in water infrastructure and retrofits where aging assets, cramped valve chambers, and restricted access are the norm. Based on the design requirements provided by the client, our Notched Flange Adaptors offer distinct advantages:

• Designed for Confined Spaces: In retrofit situations, aligning bolt holes between mating flanges is genuinely difficult, especially in cramped spaces with little room to manipulate the assembly. The notched design allows the adaptor to slide or drop into place, bypassing traditional bolt-hole alignment struggles.
• Works Seamlessly with Tie-Flanges: A Tie-flange is used when a flanged connection needs to be made without the ability to rotate the pipe. Our notched adaptors are specifically engineered to work perfectly with Tie-flanges, providing a secure, reliable joint even when one or both ends of the pipework are fixed in position.
• Faster Installation & Reduced Disruption: By eliminating the need to rotate pipes or perform complex field fabrications, installation teams can get the job done significantly faster. This minimizes downtime and disruption to live systems.
• SS316L for Long-Term Durability: While our client's application required full SS316L (2.0–3.0% molybdenum) for maximum pitting and crevice corrosion resistance, the robust design of these adaptors ensures long-term reliability in demanding environments.

Technical Details

Note: The DN900 unit requires dedicated machining to ensure the notch geometry and flange face flatness perfectly match the existing pipe OD and bolt hole patterns.

Frequently Asked Questions (FAQ)

Q: What is a Notched Flange Adaptor?
A: A notched flange adaptor is a modified flange connection designed to solve installation challenges in restricted or fixed-pipe environments. The notches allow the adaptor to be maneuvered into position when standard flanges cannot be properly aligned or rotated.

Q: Can these adaptors be used in potable water applications?
A: Yes. Similar to industry standards (such as those used by the UK water sector), when manufactured with appropriate coatings or in suitable stainless steel grades, notched flange adaptors can be used in potable water applications without compromising compliance.

Q: How do you match a DN900 adaptor to existing fixed piping?
A: We require the exact pipe outer diameter, wall thickness, and the bolt hole pattern (including the position of the fixed bolts). Our engineering team will then customize the notch dimensions and locations to ensure a seamless drop-in fit.

Q: Do you provide material test certificates?
A: Yes. Every SS316L batch is supplied with a mill test certificate (MTC) traceable to the heat number. Third-party inspection (e.g., SGS, TÜV) can also be arranged upon request.

Inquiry and Technical Support
Struggling with pipe alignment or restricted access for your retrofit project? For custom SS316L Notched Flange Adaptors, datasheets, or drawing confirmation, please submit your pipe parameters, flange standard, and site constraints through the contact form on our website.