Delayed Action Door Control - What is it? and how does it work?
Delayed Action?is a function of the?Door Closer?hydraulic cylinder. The hydraulic cylinder will hold the?door?open to allow more time to get through the?door?way.
Design considerations in Approved Document M (ADM) says that, Self-closing devices on manually operated non-powered swing doors disadvantage many people who have limited upper body strength, are pushing prams or are carrying heavy objects. (Source: Building Regs Part M1/M2 2.14)
The suggestion is that, Door furniture on manually operated non-powered doors should be easy to operate by people with limited manual dexterity…( Source: Building Regs Part M1/M2 2.16)
Maybe someone will help me where Approved Document M (ADM) refers to delayed action on non-powered doors if at all?
For powered doors ADM is clear that sensors assist doors to…stay open long enough, to permit safe entry and exit… (Source: ADM M1/M2 2.21 b)
Delayed action or swing free closing devices may be used on doors to individual rooms, but are not considered suitable for doors on circulation routes. (Source BS 8300 9.2.2 note 3) [edit from 7.3.1]
On circulation routes I normally recommend emag hold open closers [edit] which is specified in BS 8300 9.2.2 note 2, and I quote, Where the force required to open a fire-resisting door on a circulation route exceeds the limits described in 8.4.2, ( not more than 30 N from 0 to 30 degrees, and not more that 22.5 N from 30 to 60 degrees of opening cycle) an electrically powered hold-open device, either stand-alone or integral in the body of the closer, which conforms to BS EN 1155 should be installed.
Where the force required to open a fire-resisting door on a circulation route exceeds limits described in BS 8300, an electrically powered hold-open closer is advised
When it comes to door control, whether powered or non-powered doors, in my opinion it’s critical to assist these people with limited strength to get through the door before it closes.
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For this type of situation, choosing a?door closer?which?has?a 'delayed action' function can assist.
How does delayed action work?
As the user opens the?door, hydraulic fluid passes from one reservoir to another in the chamber.?The oil flow is slowed down or increased by turning the valve adjustment on the door closer to achieve the desired delay in close.?When fully opened and released, the door may partially close, then hold for maybe 25 seconds while the user moves through the door way. Then as the oil moves into the next chamber the control transfers to the next valve, this being the closing or latching valve which takes the door through the rest of the closing cycle.
How long does delayed action hold the door?
Delayed action prolongs closing time, for example to make it easier for wheelchairs or less able people to pass through the door easily.?On a fire door this should be set to a max of 25 seconds delay.?This delay is permitted from fully open to 70 degrees where the normal closing and latching valves will take over.?
How do I get delayed action to work on push-side of a door?
When fitting push-side (fig 66), an arm with more adjustment for pre-tension may be needed.?Sometimes these are called ‘star cut arm’.?The multi point location on the door closer pinion allows more pretension moving the piston in the hydraulic chamber to reach the delayed action valve.
Other resources including videos are available on Delayed action door closers. Please message me directly for further support.
Apart from references to sources, this article is largely my own opinion or interpretation of the requirements.?It is advisable to take professional advice in regard to regulations that may affect your particular project.??