Dalam dunia perpipaan industri, solusi yang hemat biaya dan efisien sangat penting—terutama dalam sistem dengan kondisi tekanan dan suhu sedang. Di antara berbagai pilihan flensa, itu flat welding flange (also known as a slip-on flange) stands out as a practical and economical choice for low-pressure pipeline systems.

This article explores the advantages, technical features, aplikasi, installation methods, and material options of flat welding flanges. Whether you’re a pipeline contractor, engineer, or procurement specialist, this guide will help you understand why flat welding flanges are a popular option in industries such as water treatment, AC, petrokimia, and general construction.

---

What Is a Flat Welding Flange?

A flat welding flange is a type of pipe flange that slides over the pipe and is then fillet welded on both the inside and outside to provide strength and leak-tightness. Berbeda dengan flensa leher las, flat welding flanges do not have a hub and are ideal for applications where pressure is relatively low and where space and budget constraints matter.

Standard references include:

• ASME B16.5 – For pipe flanges and flanged fittings

• EN 1092-1 Jenis 01 atau 02 – For European specifications

• JIS B2220 – For Japanese standard flanges

sasa lonjong manufactures flat welding flanges in a variety of sizes and materials to meet international standards and project specifications.

---

Design Features of Flat Welding Flanges

• Ukuran lubang: Slightly larger than the pipe outer diameter to allow easy insertion

• Wajah terangkat (Federasi Rusia) atau wajah datar (FF): Options depending on sealing needs

• No long tapered hub: Compact and lightweight

• Fillet welds: Applied on both sides to secure the pipe

• Lubang baut: Equally spaced to match standard bolt patterns

The simple geometry and easy alignment make flat welding flanges suitable for quick assembly, memperbaiki, and field modifications.

---

Keuntungan Flensa Las Datar

1. Cost-Effective Solution

Flat welding flanges are more affordable than weld neck flanges due to:

• Less material used

• Easier machining

• Faster installation time

• Lower welding complexity

This makes them ideal for budget-sensitive projects and large-scale piping networks.

2. Easy Installation and Alignment

These flanges are easier to align with pipes during welding. Milik mereka slip-on design accommodates minor misalignment and allows quick positioning.

• Saves labor time

• Reduces risk of installation errors

• No need for complex beveling as with butt-weld connections

3. Lightweight and Space-Saving

The absence of a hub reduces the overall weight and space requirement, making them suitable for:

• Compact equipment layouts

• Lightweight supports

• Skid-mounted systems

4. Fleksibilitas dalam Aplikasi

Flat welding flanges can be used for:

• Fluids (air, udara, minyak)

• Low-pressure steam

• Non-hazardous gases

• Non-corrosive liquids

They are common in non-critical systems that don’t require high structural strength.

5. Wide Availability and Customization

Flat welding flanges are widely produced and available in:

• Kelas tekanan: 150#, 300#, PN10, PN16

• Ukuran: DN15 hingga DN2000

• Facing types: Federasi Rusia, FF, and RTJ

• Bahan: Baja karbon, baja tahan karat, baja paduan

sasa lonjong offers quick delivery of standard and customized flat welding flanges for global projects.

---

Typical Applications of Flat Welding Flanges

● Water Supply and Drainage

Used in municipal pipelines, stasiun pompa, and wastewater treatment plants due to corrosion-resistant coatings and simple connections.

● Sistem HVAC

Flat welding flanges are ideal for air conditioning and heating pipelines, offering quick on-site adjustments and tight seals.

● Pabrik Kimia dan Petrokimia

Applied in non-critical service pipelines carrying mild chemicals, pelarut, or low-pressure steam.

● Pengolahan Makanan dan Minuman

When made from stainless steel, flat welding flanges are used in hygienic piping for beverages, dairy, and brewing.

● Power Plants and Energy Facilities

Applied in auxiliary systems such as cooling water, low-pressure return lines, and drainage networks.

---

Installation Procedure

Installing a flat welding flange requires the following steps:

1. Persiapan Pipa

   • Cut the pipe to the required length

   • Clean the pipe end to remove oil, kotoran, or burrs

2. Flange Placement

   • Slide the flange over the pipe end

   • Align the bolt holes with mating flange or template

3. Pengelasan

   • Perform a fillet weld on the inner side of the pipe end

   • Follow with an outer fillet weld around the flange face

4. Gasket Insertion and Bolt Tightening

   • Place the gasket (luka spiral, karet, dll.)

   • Insert bolts and tighten in a cross-pattern using a torque wrench

   • Follow appropriate torque sequence to ensure uniform pressure

5. Pengujian dan Inspeksi

   • Conduct hydrostatic or pneumatic testing to check for leaks

   • Visually inspect welds for quality and completeness

sasa lonjong supplies flanges with precision machining, making installation smooth and consistent.

---

Pilihan Bahan

Flat welding flanges are manufactured in a variety of materials, termasuk:

• Baja Karbon (ASTM A105, EN P245GH): Affordable and strong for general use

• Baja Tahan Karat (304, 316, 321): Corrosion-resistant for chemical and food applications

• Baja Paduan (F11, F22): Used in moderate temperature and pressure environments

• Baja Tahan Karat Dupleks: Offers superior strength and corrosion resistance

• Paduan Nikel: For specialized systems requiring chemical resistance

Surface treatments may include:

• Galvanizing

• Epoxy coating

• Pasifasi

• Pickling and polishing

sasa lonjong offers material traceability, EN10204 3.1 sertifikat, and special coatings upon request.

---

Pressure Ratings and Standards

Flat welding flanges are designed for low to moderate pressure applications:

• ASME B16.5 Kelas: 150#, 300#

• EN 1092-1 Kelas Tekanan: PN6, PN10, PN16

• JIS B2220 Kelas: 5K, 10K, 16K

Always select the correct pressure class and material based on system pressure, suhu, dan tipe fluida.

---

Inspection and Quality Control

Untuk memastikan keamanan dan kinerja, all flat welding flanges must undergo:

• Inspeksi dimensi

• Verifikasi materi (PMI)

• Flatness and facing finish check (Ra ≤ 3.2 mikron)

• Penjajaran lubang baut

• Visual inspection of welds (if factory-welded)

• Hydro or air leak testing if assembled

sasa lonjong mempertahankan ISO 9001-certified quality systems and third-party inspection cooperation (SGS, BV, TUV).

---

Mengapa Memilih sasaflange?

sasa lonjong is a professional flange manufacturer serving global customers in energy, petrokimia, air, dan proyek infrastruktur. Keuntungan utama meliputi:

• Full range of flat welding flanges in ASME, EN, DIN, JIS, and GOST standards

• Manufacturing in stainless steel, baja karbon, dan paduan khusus

• pemesinan CNC, surface finishing, and drilling

• 3.1/3.2 certified quality control and fast export support

• Ukuran khusus, pelapis, and gasket kits available

For budget-conscious projects or low-pressure pipelines, sasa lonjong delivers reliable flanged solutions with fast turnaround.

---

Kesimpulan

Flat welding flanges are a smart and economical solution for low-pressure pipeline systems across a wide range of industries. Their ease of installation, efisiensi biaya, and flexibility make them ideal for non-critical yet essential piping applications.

By sourcing high-quality flat welding flanges from sasa lonjong, customers benefit from certified materials, international compliance, and expert support—ensuring the success of every pipeline project.

---