NSV’s Dampers can be found in some of the harshest environments throughout the world and the use of high-grade materials and components ensures repeated high performance with minimal maintenance during service.

General Construction

Casing: Standard damper casings are 200mm deep (300mm for Fire Dampers) and are manufactured using 3.0mm stainless steel. NSV cases are constructed with precision to ensure the damper blades are correctly aligned thus preventing sticking, this guarantees fault-free damper operation.

Blades: FGS-01, NSD-01 and NSD-02 type dampers all utilise double skin 2.0mm stainless steel while NPR-01 and NND-01 type dampers utilise single skin 1.0mm stainless steel. Blades are accurately sized to ensure that they do not protrude beyond the damper casing when in the open position.

Bearings: To facilitate smooth operation, blade shafts rotate in high temperature oil-impregnated phosphor bronze bearings.

Flanges: 50mm or 75mm (depending on damper size) stainless steel flanges are formed from the damper case and have an additional return edge to give rigidity to the damper case. 

Flanges can be drilled to NSV’s standard detail or client specification and in accordance with BS EN ISO 15138:2007

Control and operation: The dampers can be manufactured for manual use with a lockable hand quadrant or with either electrical or pneumatic actuators for a wide variety of control systems including full integration into automated HVAC management systems. Various position feedback apparatus are also available to suit each installation.

Suitable for safe or hazardous area applications, our dampers are used both offshore and onshore at petrochemical facilities, renewable energy installations and in the nuclear industry

Sizes: Dampers are available from 100mm Square up to a maximum clear area of 1200mm square with a general depth of 200mm (300mm on the FGS-01). Sizes above this can be achieved using mullions. Circular dampers are also available to suit specific applications. 

Dampers Overview

Fire Dampers FGS-01

NSV Fire Dampers are used to prevent the spread of fire and protect the integrity of fire-resistance rated bulkheads and decks where they are penetrated by ventilation ducts. This ensures that ultimate protection is provided for personnel and equipment. 

The NSV FGS-01 Fire Damper has been designed and certified for installation into fire rated divisions. These range from AO up to H120 in both vertical and horizontal configuration. NSV’s Fire Dampers have been tested at the Warrington Fire Research Centre and undergone the Department of Energy Hydrocarbon Fire Resistance Tests.

In addition to the above tests, fire dampers have also been approved by Lloyds Register of Shipping and Det Norske Veritas (DNV) for installation in A0, A60, H60 and H120 fire rated divisions.





Shut Off Dampers NSD-01

NSV Shut Off Dampers are designed to completely isolate ventilation ductwork or sections of mechanical components for operational and maintenance purposes, the design incorporates blade sealing faces to ensure air leakage is kept to an absolute minimum when closed. 








 Volume Control Dampers NSD-02

Volume Control Dampers are designed to control and balance a ventilation system by limiting the amount of air able to pass through the blades without providing a complete seal.  






Pressure Relief Dampers NPR-01

Pressure Relief/Control Dampers are designed to maintain a positive pressure within offshore and onshore modules, therefore preventing the ingress of hazardous gases. Pressure relief dampers are counter

balanced and once configured to operate at a threshold pressure during installation they will always maintain the desired pressure within the module.

Non-Return Dampers NND-01

Non-Return Dampers are designed to control the direction of airflow within a HVAC system. Utilised in Analyser House modules and Air Handling Unit’s, NSV’s Non-Return dampers are gravity operated and will open with an increase in upstream pressure and close with a drop in pressure or a downstream airflow to ensure airflow only travels in the right direction.


Blast Damper BD-01

NSV ATEX rated blast dampers are designed to be installed on penetrations within blast resilient walls and bulkheads. The BD-01 blast damper allows ventilation air to pass through during normal operation and in the event of a blast will close is less than 25 milliseconds to protect personnel and equipment on the non-blast side.

The dampers are constructed from 5.0mm stainless steel feature a manual reset and are latched with adjustable tensioners to prevent nuisance trips.



Nuclear/Biological/Chemical Damper

NSV’s Nuclear/Biological/Chemical Damper (NBC) are designed for full integration into NBC safety systems and provides automated emergency closure to prevent the passage of airborne contamination by radioactive, biological or chemical substances through the ventilation system. 

The unique and innovative design of the cylindrical NBC Dampers ensures a completely airtight seal through 10,000 operations.