INTUMESCENT FIRE CLAMP INTERNAL TYPE
Trade Name ASTRO NT CLAMP 

Introduction

The purpose of this document is to give guidance to approved contractors and suppliers who are engaged in the fire stopping of service penetrations in fire rated structures using the Astro Internal Fire Clamp.

All service holes through floors and compartment walls must be fire stopped to prevent the passage of fire, smoke and hot gases.

The key points for intumescent passive fire protection products are:

• Prevent the spread of fire, smoke and hot gases through a building by containing it in the compartment of origin.
• Maintain the integrity of escape routes from a building.
• Reduce loss or damage to property from the effect of fire and smoke.
• Maintain pressure differential between compartments and ventilation channels.

THE ASTRO NT CLAMP SYSTEM

With metal trunking being such an excellent medium for heat conduction and coupled with the flammability and conductivity of cables, the need to fire stop metal trunking internally is paramount in containing a fire's spread.

PVC cable sheaths contain about 50% Chlorine which, when submitted to temperatures exceeding 140oC, will start to vaporize, emitting highly corrosive Hydrogen Chloride gas. If water vapour is present and combines with the gas forming Hydrochloric acid, the corrosive effect on the cabling and metal trunking could cause irreparable damage to a building's power and communication systems, which may continue well after the fire itself has been extinguished.

Consisting of a pre-fabricated metal frame with a series of vertical steel fins lined with a heat reactive graphite, Astro NT Clamp has been designed to fire-stop cables, trunking and pipes.

They are able to accommodate multiple penetrations either isolated or grouped together. Tested in accordance with BS476 Part 20: 1987, ASTRO NT Clamp has achieved integrity and insulation ratings in excess of 240 minutes in both wall and floor configurations

• Suitable for all metal trunking where it breaches fire compartment floors and walls.
• Under raised access floors where cabling is often abundant, i.e. computer, switch and security rooms.
• Retrofit: Perfect for installations where frequent cable alterations occur.

Availability

* This model has a slide fit retaining devise replacing the twist and lock mechanism.

Installation

ASTRO NT Clamp consists of 2 or 4 steel fins (depending on whether 2 or 4 hour fire resistance is required) which are welded at equidistant centres to a steel plate. The inner and outer surfaces of the fins are lined with an intumescent sheet. The ASTRO NT Clamp is mechanically restrained within the trunking by means of a twist and lock mechanism which is riveted through the top of the ASTRO NT Clamp and partially lined with intumescent graphite sheet

The 50mm x 50mm NT clamp has a slide fit mechanism replacing the twist and lock mechanism

Suitable for all metal trunking where it breaches fire compartment floors and walls.
Under raised access floors where cabling is often abundant, i.e. computer, switch and security rooms.
Retrofit: Perfect for installations where frequent cable alterations occur

ASTRO NT Clamps do not require renewal in the event of cable alteration. Thus ensuring this protection is permanent without the potential loss or damage which effect other system types

Compliance

Astroflame intumescent internal clamps are manufactured in the EU, meeting the highest quality standard in compliance with ISO EN 9001:2000 . For fire test certification contact Astroflame Fireseals technical department.

Fire Test or Assessment Reports

Storage and disposal

Astroflame Intumescent Internal clamps are not affected by the outdoor environment. However for long term storage and ease of installation, it is recommended that they should be stored indoors. No shelf life is given as this product will not deteriorate in storage.

For additional testing, certification or technical information please contact ASTROFLAME FIRESEALS LTD.

Issue 01/03