Product Description

TWPro 125mm Twin Wall Insulated 30 Degree Bend – Matt Black

Model: 37-125-032

Create a controlled change of direction in a 125mm insulated chimney with the TWPro 30 Degree Twin Wall Bend. This two-segment bend changes the flue direction by 30° and forms part of the TWPro matt-black chimney system.

Installers can use one bend to change direction or two bends to create an offset around an obstacle. However, always check the dimensions and permitted chimney route before ordering.

The bend features a 316L stainless-steel inner casing, mineral wool insulation and a matt-black 304-grade stainless-steel outer casing. In addition, the push-fit joint and locking band create a secure connection to matching TWPro components.

Product at a Glance

• 125mm nominal internal flue diameter
• 30° fixed chimney bend
• Two-segment construction
• Changes the direction of a TWPro chimney route
• Use two bends to create a calculated offset
• Suitable for internal and external chimney systems
• 316L stainless-steel inner casing
• 304-grade stainless-steel outer casing
• High-temperature matt-black external coating
• 25mm high-density mineral wool insulation
• Push-fit FitSystem connection
• Supplied with a locking band
• Suitable for compatible solid-fuel, gas and oil appliances
• HETAS approved and CE marked
• T600 temperature classification
• G50 soot-fire resistance classification
• 50mm declared distance to combustible materials
• Product model: 37-125-032

Important Angle Information

This component has a fixed angle of 30°, not 37°. Model 37-125-032 identifies the TWPro 125mm two-segment 30-degree bend.

The bend changes the chimney direction by 30° from its original route. Therefore, check the product drawing and dimensions before planning an offset.

If your chimney design requires a different angle, choose the correct TWPro bend rather than trying to alter this component.

What Is a 30 Degree Twin Wall Bend Used For?

A chimney should rise as straight and vertically as possible. However, joists, roof structures, gutters and other parts of a building can sometimes block the ideal route.

A 30° bend allows the chimney to move away from an obstacle while maintaining an upward path. A second bend can then return the chimney to its original direction.

As a result, installers commonly use two matching bends to form an offset. The distance between those bends determines the amount of sideways movement.

Key Features

• Creates a fixed 30° change in chimney direction
• Two-segment design provides a smooth flue path
• Suitable for creating offsets with a second matching bend
• Maintains a continuous 125mm internal flue diameter
• High-grade stainless-steel inner and outer casings
• Insulation helps maintain the flue-gas temperature
• Fully welded construction provides strength and durability
• Matt-black finish complements black stoves and chimney pipes
• Push-fit joint supports straightforward installation
• Locking band secures the connection
• Compatible with matching 125mm TWPro chimney components

TWPro 125mm 30 Degree Bend Specification

• Download the TWPro Matt Black information sheet
• View the TWPro installation diagram
• Read why we recommend TWPro twin-wall flue
• Product type: fixed insulated chimney bend
• Nominal internal diameter: 125mm
• Bend angle: 30°
• Construction: two segment
• Inner casing: 0.4mm 316L-grade stainless steel
• Outer casing: 0.4mm 304-grade stainless steel
• Outer finish: high-temperature matt-black coating
• Insulation: 25mm high-density mineral wool
• Construction method: fully welded
• Joint method: push fit with locking band
• Temperature classification: T600
• Declared distance to combustible materials: 50mm
• System warranty: 25 years, subject to terms and conditions
• Paint-finish warranty: 2 years, subject to terms and conditions
• Product code: 37-125-032

Approvals and Classifications

• HETAS approved
• CE marked
• EN 1856-1 T600 N1 W V2 L50040 G50
• EN 1856-1 T200 P1 W V2 L50040 O20

The T600 designation classifies the relevant chimney arrangement for flue-gas temperatures up to 600°C. In addition, the G50 designation identifies a soot-fire-resistant arrangement with a declared distance of 50mm from combustible materials.

However, the correct classification depends on the appliance, fuel and complete chimney design. Therefore, follow the appliance instructions and TWPro installation guide.

Suitable Applications

This 125mm TWPro insulated bend may suit correctly specified heating appliances such as:

• Wood-burning stoves
• Multifuel stoves
• Compatible solid-fuel appliances
• Gas coal-effect fires
• Gas boilers
• Oil-fired boilers
• Other compatible gas and oil appliances

However, the appliance outlet size alone does not confirm the correct chimney diameter. First, check the appliance instructions. Next, confirm the required chimney classification. Finally, make sure the full route complies with Building Regulations and TWPro installation requirements.

Creating a Chimney Offset

Installers normally create an offset by using two bends of the same angle. The first bend moves the chimney away from its original line. Then, the second bend returns it to a parallel or vertical route.

The pipe length between the bends controls the amount of sideways offset. A longer intermediate section usually creates a greater offset.

Therefore, check the TWPro offset table or product dimensions before ordering. Also, include the joint overlaps when calculating the chimney height and offset.

Do not estimate the offset from the bend angle alone. The final measurement depends on the bend dimensions, intermediate pipe length and joint engagement.

Keep the Chimney Route as Straight as Possible

Every bend creates some resistance to the flue gases. Therefore, a straight vertical chimney will normally provide the simplest route and support good draught.

Only add bends when the chimney must avoid an obstacle or meet a necessary change in direction. Furthermore, keep the number of bends within the limits set by the appliance instructions, TWPro guidance and Building Regulations.

Avoid unnecessary or complicated offsets. They can make chimney sweeping more difficult and may affect appliance performance.

Two-Segment Construction

This bend uses two formed segments to create the 30° angle. The design provides a controlled change of direction while maintaining the 125mm internal flue route.

Fully welded joints provide strength and help create a durable component. Meanwhile, the matt-black surface gives the bend a smooth and professional appearance.

The fixed construction does not allow angle adjustment. Therefore, do not twist or modify the bend to achieve a different angle.

How Twin-Wall Insulation Helps

The mineral wool layer sits between the inner flue and outer casing. This insulation helps retain heat as the combustion gases pass through the bend.

Warmer flue gases can support chimney draught and help reduce condensation. In addition, the insulation reduces heat transfer to the outer casing compared with single-wall stove pipe.

However, the outside of the bend can still become hot during use. Therefore, maintain the required clearances and prevent accidental contact where necessary.

Strong Stainless-Steel Construction

The inner casing uses corrosion-resistant 316L-grade stainless steel. This surface carries combustion gases through the bend.

Meanwhile, the outer casing uses 304-grade stainless steel with a high-temperature matt-black coating. As a result, the bend provides durable protection and matches other TWPro matt-black components.

This combination makes the bend suitable for visible internal or external chimney routes when installers fit and support it correctly.

Installation Guidance

First, confirm the required bend angle and offset dimensions. Next, check the bend for damage and make sure both joint ends remain clean.

Push each connection fully into the adjoining TWPro component. Then secure the joints with the correct locking bands. Finally, check that the complete offset remains aligned, supported and fully engaged.

Install every component in the direction shown in the TWPro instructions. Correct joint orientation helps keep condensate and combustion deposits inside the chimney.

Do not cut, reshape or attempt to alter the bend angle. Instead, select the correct bends and pipe lengths for the planned route.

Supporting a Chimney Offset

An offset can create sideways forces and add weight to the surrounding joints. Therefore, provide suitable support above and below the change in direction.

Do not rely on locking bands alone to support the chimney. Instead, use the correct wall bands, base supports, ceiling supports or roof supports for the installation.

The installer must also consider the maximum distance between supports and the permitted unsupported chimney height. Always follow the TWPro installation guide.

Distance to Combustible Materials

Maintain at least 50mm between the TWPro insulated chimney and combustible materials for the relevant T600 G50 system arrangement.

Combustible materials can include timber, roof structures, insulation, furniture and other heat-sensitive products. Furthermore, plasterboard may form part of a timber structure and should not automatically count as non-combustible.

Measure the clearance from the closest part of the bend or chimney outer casing. This point matters because an offset may bring the flue closer to nearby building materials.

Do not fill the required air gap with insulation unless the manufacturer supplies a tested component for that exact purpose.

Does the Bend Include a Locking Band?

The TWPro joint uses a locking band to secure the push-fit connection. Fit the supplied band in the correct position and make sure it closes fully.

Depending on how the bend connects within the chimney, the adjoining component may provide the locking band for the second joint. Therefore, check that you have the required band for every connection before starting the installation.

Can the Bend Pass Through a Wall or Ceiling?

A chimney bend should normally remain visible and accessible for inspection rather than sitting inside a building penetration or concealed space.

Use straight TWPro pipe with the correct fire-stop, support, sleeve or flashing components where the chimney passes through a wall, ceiling, floor or roof.

Plan the offset so the bend joints remain clear of the penetration and accessible for inspection. Always follow the manufacturer’s required joint positions and clearances.

Can I Mix TWPro with Another Chimney Brand?

Do not connect this bend to another manufacturer’s twin-wall chimney unless both manufacturers provide written approval.

Different chimney systems can use different outer diameters, joint depths, insulation specifications and locking methods. Therefore, components with the same stated internal diameter may not connect safely.

Using matching TWPro parts helps preserve the tested system classification and creates a secure, consistent chimney installation.

Maintenance and Chimney Sweeping

Bends can collect more soot and combustion deposits than straight vertical pipes. Therefore, the complete chimney must provide suitable access for cleaning.

Arrange chimney sweeping at intervals that suit the appliance, fuel and frequency of use. During servicing, inspect the bend, locking bands, welded seams and surrounding supports.

Replace the bend if it becomes badly corroded, distorted, damaged or insecure. Furthermore, arrange a professional inspection if you notice smoke leakage, poor draught or a change in appliance performance.

Why Choose TWPro?

TWPro combines a durable 316L stainless-steel inner casing with a strong 304-grade stainless-steel outer casing. In addition, the mineral wool insulation helps retain heat and supports a stable flue temperature.

The FitSystem push-fit joint makes assembly straightforward, while the locking band secures each connection. Furthermore, the range includes matching pipes, bends, tees, supports, flashings and terminals for a complete chimney installation.

Finally, the smooth matt-black finish creates a professional appearance for modern and traditional properties.

Why Buy from SNH Tradecentre?

• Specialist stove, chimney and flue-system supplier
• Extensive range of matching 125mm TWPro components
• Practical product advice from an experienced team
• Nationwide UK delivery options
• Secure online ordering
• Trade counter in Birchington, Kent
• Support before and after your purchase

Need help calculating an offset or selecting the correct pipe lengths? Call SNH Tradecentre on 01843 842727 before ordering.

Frequently Asked Questions

Is this a 30-degree or 37-degree bend?

This product is a fixed 30° bend. Model 37-125-032 identifies the TWPro 125mm two-segment 30-degree bend.

What diameter is the bend?

It has a nominal internal flue diameter of 125mm, which is approximately 5 inches.

Can I use two bends to create an offset?

Yes. Installers commonly use two matching 30° bends with a straight pipe section between them to create an offset.

How do I calculate the offset?

The offset depends on the bend dimensions and the effective installed length of the pipe between the two bends. Check the TWPro dimensions before ordering.

Can I adjust the angle?

No. This is a fixed two-segment 30° bend. Do not twist, cut or reshape it.

Can I use it with a wood-burning stove?

Yes, it may suit compatible wood-burning and multifuel appliances. However, check the required diameter and chimney specification in the appliance instructions.

How far must it remain from combustible materials?

The relevant T600 G50 system has a declared distance of 50mm from combustible materials. Measure this clearance from the nearest part of the bend’s outer casing.

Can I install the bend inside a wall or ceiling?

Keep bend joints accessible and away from building penetrations. Use straight pipe with the correct tested components where the chimney passes through walls, ceilings, floors or roofs.

Does the bend need support?

Yes. An offset can place sideways forces on the chimney, so use the correct TWPro supports above and below the change in direction.

Can I connect it to another chimney brand?

Do not mix chimney brands unless both manufacturers provide written approval. Similar-looking components may use incompatible connections.

What is the product model?

The product model is 37-125-032.