Lap Joint Flanges vs Slip On Flanges

by kalpataru | Jul 6, 2024 | Blog | 0 comments

Flanges are vital components in piping systems enabling secure connections between pipes, valves & other equipment. Among the various types, the slip on flange & lap joint flange are widely used across industries for their specific applications. Choosing between a lap joint flange & a slip on flange depends on your system pressure, alignment needs & maintenance frequency. Slip on flanges are cost-effective & simple to install, while lap joint flanges offer better flexibility & reusability in complex piping systems. Understanding these differences helps in selecting the right flange for your needs. This blog will explain their features & help you to decide which one is best for you.

At Kalpataru Piping Solutions, we manufacture high-quality slip on flanges & lap joint flanges by using stainless steel, carbon steel & alloy steel material. Our products are designed to meet international standards to use in a wide range of industrial applications. Contact us today to get the right flange solution for your project.

What is Slip On Flanges?

Slip on flanges are important components in piping systems designed to slide over the pipe end & are welded both on the inside & outside for a secure connection. Their design allows for easy alignment during installation to make it the best choice for low to moderate pressure applications. These flanges can also function as lap joint flanges when used with Type B or Type C stub ends for various other industrial applications. Slip on reducing flanges are designed to connect different pipe sizes within a larger flange, enhancing compatibility across piping systems. They are manufactured by using materials such as carbon steel, stainless steel, alloy steel, duplex stainless steel & nickel alloys depending on factors like the pressure, temperature & corrosion resistance. To ensure long-term reliability & high-pressure performance , they are welded with precision by skilled professionals. Proper installation helps to prevent damage & ensures smooth, efficient system operation.

Key Advantages of Slip-On Flanges:

Discover the benefits of Slip-On Flanges for low-pressure piping systems. Ideal for diverse industrial applications.

Easy Installation: Simplifies pipe alignment and reduces welding time.
Cost-Effective: An economical option, especially for systems under moderate pressure.
Versatile Use: Adaptable to a variety of industries and compatible with different pipe sizes.
Efficient Flow: Offers minimal turbulence and pressure loss within the piping system.

What is a Lap Joint Flange?

A lap joint flange also called a lap flange. It consists of a stub end & a backing flange. The stub end looks like a short pipe section with a weld bevel on one side & a flared end that matches the gasket face of a weld neck flange. It usually measures between 1/4″ & 3/8″ thickness by attaching to the pipe with a fillet weld. The backing flange has standard dimensions but lacks a raised face, featuring instead a small shoulder or pipe hole. Due to its strong features, the lap joint flange & stub end are well suited for piping systems that need frequent maintenance, inspection or realignment. They are manufactured with materials including stainless steel, carbon steel, alloy steel, duplex stainless steel & nickel alloys. The material selection depends on factors such as operating pressure, temperature, corrosion resistance & fluid type.

Advantages of Lap Joint Flanges:

Lap Joint Flanges offer easy alignment, reduced bolt stress, and cost-effective maintenance ideal for systems requiring frequent disassembly or inspection.

Alignment Flexibility: The rotatable backing flange allows easy alignment of bolt holes, even in systems with slight misalignments.
Ease of Maintenance: Its design enables quick access for maintenance & inspection without removing the entire flange assembly.
Cost Effective: Used for large diameter piping systems or where frequent disassembly is required to reduce long term maintenance costs.
Leak Prevention: The stub end is welded to the pipe for ensuring a secure seal & minimizing the risk of leakage around the joint.

We supply high-quality lap joint flanges in a wide range of materials, including carbon steel and stainless steel lap joint flanges, engineered to meet various industrial standards and application requirements.

Lap Joint Flange vs Slip-On Flange: Key Differences

Understand the key differences in flexibility, pressure handling, welding requirements & sealing performance. Make informed decisions when selecting the right flange type for efficient, safe & cost-effective piping installations.

Feature	Lap Joint Flange	Slip On Flange
Flexibility and Maintenance	Allows rotation of the flange around the stub end for easy bolt hole alignment and simple disassembly.	Fixed in place once welded, offering limited flexibility and not ideal for frequent removal.
Pressure Rating	Typically used in medium-pressure applications; not recommended for very high pressures due to design limits	Suitable for low to medium pressures; welding limits may restrict use in high-pressure systems.
Size and Variety	Available in larger sizes, often preferred for big-diameter pipes needing flexible installation options.	Available in standard sizes, mostly used with small to medium diameter pipes.
Installation & Welding	Lap joint flanges use a stub end that is welded to the pipe while the backing flange remains unwelded. It requires more precise welding on the stub end & more complex installation process.	Slip-on flanges slide over the pipe and are welded on both the inside & outside for making alignment easier & allowing for quicker installation without the need for highly specialized welding.
Cost & Leak Prevention	Slip-on flanges tend to be more cost effective due to fewer welds & easier fabrication. Due to their flange lip sticking out past the pipe, they don’t support leakage.	Lap joint flanges are more expensive due to the welding of the stub end but offer a better seal because the flange stays flush with the pipe to prevent leaks.

Lap Joint Flange vs Slip-On Flange: Applications

Lap joint flanges are ideal for systems requiring frequent disassembly, alignment adjustments, or corrosive environments, while slip-on flanges are perfect for low-pressure applications needing easy & cost effective installation. Understand where each fits best in industrial piping setups:

Industry	Lap Joint Flange	Slip On Flange
Oil and Gas	Best for low-pressure pipeline connections (Class ≤600).	Ideal for systems handling corrosive media that need frequent cleaning or replacement.
Water Treatment	Water TreatmentCommonly used for transporting clean water in low-cost, stable setups.	Preferred in wastewater treatment where high corrosion resistance is required.
Chemical Industry	Suitable for non-corrosive fluids like cooling water systems.	Excellent choice for handling strong acids or alkalis; stub ends can be made from special alloys like Hastelloy.
Construction	Used in HVAC low-pressure pipelines and building water supply systems.	Less common, as these systems typically don’t require frequent maintenance.

Frequently Asked Questions About Lap Joint Flanges Vs Slip On

When to choose lap joint flanges vs slip on flanges?

Use lap joint flanges when your system needs frequent disassembly or maintenance, such as in chemical, food, or pharma industries.

When to choose slip on flanges vs lap joint flanges?

Choose slip-on flanges for permanent installations where maintenance is minimal—ideal for water, HVAC, and oil & gas systems.

Can extra welding make a slip-on flange stronger?

Adding more welds can distort or damage the flange. Slip-on flanges are not made for full-strength welding.

Does a lap joint stub end need to match the pipe material?

You can mix materials, like using a carbon steel pipe with a stainless steel stub end to reduce costs and resist corrosion.

Can slip-on and lap joint flanges be used together?

Their face types differ, and mixing them can cause improper sealing and leaks.

What type of weld is a slip on flange?

Slip-on flanges require fillet welds on both the inside and outside of the flange.

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