4 Inch Slip On Flange Pn16

At Kriloha Gaskets & Hardware, we recognize that mid-bore fluid processing networks require components that seamlessly balance robust mechanical security with standardized line flexibility. Our 4-Inch (DN100) Forged Slip-On (SO) Raised Face (RF) PN16 Flanges represent our engineered answer for “High-Load-Joint-Security” and “Zero-Flexing-Integrity” across essential processing arrays. As a leading premier manufacturer and supplier of integrated flow control elements and pipeline hardware, Kriloha utilizes automated multi-axis production workflows to ensure that our forged slip-on configurations provide superior mechanical longevity compared to unpredictable cast alternatives.

The engineering of our metric slip-on program is founded on Microstructural Uniformity and Deflection-Resistant Flatness. By forcing certified steel stock through controlled hot-forging paths rather than relying on lower-cost casting alternatives, we completely eliminate internal gas pockets, casting porosities, and structural micro-cracks. Available in ASTM A105N Carbon Steel (normalized for exceptional impact toughness) or ASTM A182 Stainless Steel (Grades 304L/316L for high-purity or marine protection), the internal metal grain structure smoothly traces the contour of the flange ring and low-profile hub. This provides the component with an exceptional structural modulus, allowing it to withstand high bolt-torque demands across the metric bolt circle without warping or undergoing structural relaxation over time. At Kriloha, we precision-machine the Raised Face (RF) sealing surfaces on advanced CNC turning centers, finishing them with controlled phonographic serrations ( finish) that firmly anchor the gasket matrix to eliminate fluid bypass or blowout risks during sudden system pressure cycles.

Manufacturing and provisioning these critical flow-control connection pieces involves strict Dimensional Tolerance Checks, Volumetric Material Inspections, and Face Roughness Calibration. We collaborate directly with your project engineering, procurement, and facility maintenance teams to supply precise internal bores tailored to standard pipe outer diameters and unique wall-thickness schedules. By choosing Kriloha Gaskets & Hardware, you are investing in a “Future-Proof” industrial partnership that prioritizes your system’s lifetime reliability through superior metallurgy and micro-tolerance engineering.

Primary Industrial Applications

Moderate-Pressure Plant Utilities: Ideal for main factory utility headers distributing industrial water, cooling tower loops, compressed air networks, and non-corrosive gas piping operating under PN16 parameters.
Municipal Water & Sewage Infrastructure: High-volume provisioning for large-scale water treatment headers, municipal pump station manifolds, water storage tanks, and environmental drainage lines.
Commercial HVAC & Cooling Systems: Reliable connection interfaces for commercial facility heating lines, open/closed cooling towers, and large-chiller water distribution grids.
Midstream Hydrocarbon & Petroleum Lines: Heavy-duty, economical connection joints for crude oil transport manifolds, storage terminal trunk lines, and fuel oil distribution networks where fluid corrosion risks are minimal.
Modular Industrial Process Skids: Compact structural mounting flanges used by equipment manufacturers to link prefabricated mid-diameter piping manifolds directly to raised-face valves, strainers, inline instruments, and storage vessels.

Frequently Asked Questions (FAQs)

What are the standardized bolt hole configurations for a 4-inch / DN100 PN16 flange?

According to the modern EN 1092-1 / DIN dimensional standard for a PN16 pressure rating, a DN100 (4-inch equivalent) flange features an outer diameter of 220 mm and a pitch circle diameter (PCD) of 180 mm. It utilizes 8 bolt holes designed to accommodate M16 size bolts.

What is the structural difference between a Slip-On (SO) flange and a standard Flat Plate flange?

While both types slide over the pipe outer diameter and utilize double fillet welding, a standard plate flange is completely flat and collarless. A Slip-On flange features a low-profile raised hub or collar surrounding the center bore. This hub provides additional structural reinforcement at the weld zone, helping to distribute pipeline stresses and making it better suited for slightly higher mechanical loads or vibration profiles compared to a completely flat, hubless plate flange.

What specific welding configuration is required to install a metric Slip-On flange?

A slip-on flange requires a standard double fillet weld setup for proper code-compliant installation:

One robust fillet weld around the exterior where the hub neck meets the outer diameter of the pipe wall.

A secondary fillet weld inside the bore, where the pipe end is slid back slightly (typically equal to the pipe wall thickness plus 3mm) from the flange face to prevent heat or weld spatter from damaging the machined sealing surface during field welding.

Can a carbon steel Raised Face (RF) flange be safely bolted to a Flat Face (FF) Cast Iron valve?

It is highly recommended not to mate a Raised Face steel flange directly to a Flat Face cast iron component. Because cast iron is brittle, the concentrated clamping force generated by the raised face inside the bolt circle creates a bending moment that can crack or fracture the expensive cast iron valve body when torque is applied. Like-to-like face configurations are best engineering practice.

Are Material Test Reports (MTRs) provided with these forged flanges from Kriloha?

At Kriloha Ltd., quality assurance is completely non-negotiable. Every shipment from our facility can be accompanied by comprehensive Material Test Reports (MTRs) confirming exact chemical compositions, structural hardness values, yield/tensile strength data, heat treatment records, and explicit compliance with international industrial standards to guarantee complete code traceability.