TH78 beak‑type gasket

The TH78 Gooseneck gasket is a critical component in Hidden Sash aluminum systems. Engineered with a specific geometry and high-grade EPDM, it completes the window’s air and water tightness circuit. Designed for the TH78 series, it prevents energy loss and weathering while minimizing mechanical pressure on hardware, ensuring stable and long-term performance for operable units.

This product has only one variant.

Description

EPDM Gooseneck Sealing Gasket TH78

A Specialized Air-Sealing Component for Concealed-Sash Thermal Break Hinged Systems

In modern aluminum door and window systems, the final insulation performance depends not only on the precision of the profile itself, but also on the sealing components that control the infiltration of air, moisture, and energy loss. The gooseneck gasket for TH78 is specifically designed for concealed-sash thermal break hinged doors and windows TH78, and its role is to create precise engagement at the contact point between the sash and the frame, completing the system’s air-sealing circuit.

Technical Structure and Function of the TH78 Gooseneck Gasket

The name of this gasket comes from the shape of its cross-section. Its profile is designed to sit securely in the dedicated groove while being compressed in a controlled manner when the sash closes, creating a stable sealing line for both water and air.

In the TH78 system, this gasket, with its specialized geometry, helps reduce air leakage from structural joints and directly contributes to improving the thermal efficiency of the window. In concealed-sash systems, where functional clearances and facade continuity are especially sensitive, selecting the correct gasket size and compression level is even more critical.

Why Is a TH78-Specific Gasket Necessary?

One of the most common mistakes in thermal break system assembly is using similar but incompatible gaskets. Even when some profiles look similar, differences in profile width, groove depth, engagement lip height, and required compression level mean that each gasket performs correctly only in its intended system.

Dimensional compatibility with TH78: This gasket is designed according to the geometry of the 78 mm system and must match the seating area and compression zone of that specific system.
Prevention of air-sealing failure: Using an incompatible gasket may lead to incomplete seating in the groove, gaps at contact points, and reduced insulation performance.
Prevention of excess pressure on the sash and hardware: If the gasket is too thick or mismatched, it can create long-term stress on the hardware, make sash closing harder, and reduce the service life of the system.
Preservation of visual quality in concealed-sash systems: In concealed-sash designs, incorrect sealing components can affect not only technical performance but also final adjustment and the uniformity of sight lines.

EPDM Material and Its Performance Advantages:

This gasket is made from EPDM, a material widely regarded as one of the most standard and reliable sealing materials in aluminum door and window engineering due to its high environmental stability.

UV and ozone resistance: Suitable for long-term outdoor exposure under sunlight and changing weather conditions.
Thermal stability: Retains flexibility across a wide temperature range without cracking or becoming brittle.
Proper elastic recovery: Maintains resilience after repeated opening and closing cycles.
Durability against moisture and environmental wear: Helps maintain long-term air-sealing and water-sealing performance.

Choosing the right gasket in thermal break systems has a direct impact on the final quality of the project. In the concealed-sash TH78 system, using a gooseneck gasket matched to the profile geometry is essential for stable air sealing, smooth sash operation, and long-term durability.

Why Alaks Is the Engineering Backbone of Your Projects?

Purchasing hardware and sealing gaskets is not just a commercial transaction; it is a guarantee of structural quality and durability. As the largest hardware supplier in Iran, Alaks provides a comprehensive portfolio of all required components, from the most complex locking mechanisms to the most specialized EPDM gaskets, eliminating the need to search across the market.

We are not just a seller. Alaks is the only holder of the standard mark in this field, and supplies its products with a valid warranty and unconditional warranty coverage to give full peace of mind to manufacturers and end clients. Before purchasing, benefit from our technical consulting team to make the most accurate selection based on your project’s budget and technical specifications. At Alaks, standard quality is not just a slogan; it is our identity.

For hardware purchasing and pricing inquiries, please contact the sales department: 📞 WhatsApp: +98 912 006 7165.