Marine and offshore ventilation systems use dampers to balance airflow, shut off duct routes, relieve pressure and limit backflow. Selection should start with the ventilation requirements of each area rather than a specific product.
Define the ventilation requirements of each area
Process areas, machinery spaces and accommodation areas have different ventilation needs. Hazardous area classifications introduce further requirements. Airflow balancing, shut-off, pressure relief and backflow prevention may be needed together rather than as alternatives.
Damper categories also overlap: opposed-blade describes a blade arrangement, while volume control, shut-off and airtightness describe operating duties or performance. Defining the required functions first makes it easier to identify the appropriate damper type.
Balancing dampers: adjusting airflow distribution
Halton UTP balances airflow in high-pressure ductwork; UTG, UTA, and UTT also offer airflow adjustment for suitable applications. Adjusting the blade position changes resistance in the branch, allowing airflow to be set during commissioning. Operation options depend on the selected model and configuration.
Selection should account for the design airflow, duct operating pressure and pressure drop at the intended blade position, with sufficient adjustment range for commissioning. Actuation alone does not provide pressure-independent constant airflow control; this depends on the complete control arrangement.
Shut-off dampers: isolation and leakage performance
Halton UTG and UTA combine gastight shut-off with airflow balancing. UTK and UTT also provide shut-off options, depending on the required leakage performance and operating conditions.
Selection should confirm the actuation method, fail-safe position and permitted closed-blade and casing leakage at the specified differential pressure. Airtightness does not imply zero leakage: the selected size and configuration must meet project leakage requirements.
Pressure relief and backflow prevention
Pressure relief and backflow prevention address different needs in a ventilation system. Halton BRD provides one-way pressure relief, with the opening pressure adjusted using counterweights, while BLD prevents reverse airflow through the ductwork. Both operate mechanically without an actuator or motor.
Selection should confirm the opening differential pressure, installation orientation, airflow direction, operating pressure and permitted reverse leakage, as applicable. Final counterweight adjustment for BRD is carried out during on-site commissioning.
Selection considerations beyond airflow performance
For actuated dampers, control signals, position feedback and the response to loss of power or air supply should be aligned with the project control philosophy. Where specified, damper operation should be coordinated with fans, fire and gas detection, and related ventilation equipment.
Fire safety should be considered separately from airflow management. Where ventilation ducts pass through “A” class divisions, the appropriate Halton fire and gas damper should be selected according to the required fire rating and applicable approval requirements.
Taken together, these requirements guide the selection of the right damper combination for each application. Explore Halton’s airflow management dampers and controllers.
