Saturday, May 7, 2016

Dry and Pre-Action Pipe Valves

External reset dry valve is shown below.  Internal inspections are still required even though an external reset feature exists.  System may be lacking proper signage:


Side view.  Recommend alarm line 1/4 turn ball valve (indicated with arrow) be sealed, chain locked or electrically supervised in open position.  If this 1/4 turn trim valve is closed no alarms will result on dry valve activation.


Valve pictured below is a dry valve, originally it was a wet system.  A water flow switch remains installed (see arrow on left), the water flow switch vane has been removed from the riser (see arrow on right).  The wet-to-dry conversion was likely a result of one or more failures due to loss of heat in the structure.


A close up of the removed vane from the water flow switch:


At the same riser, note the electrical heat trace [unplugged - probably warm at the time of this inspection]. Who is responsible for plugging this in?



Dry face plate gasket, slight tear is evident:


Comments on the condition of this riser should be made on the inspection report:


The photo below shows a dry valve with both the alarm test and alarm line 1/4 turn ball valves cloed.  This is incorrect.  Normally the alarm line is open and the alarm test is closed [except during inspections].  Signs are required for these important trim valves.  Best practice is to seal, chain lock or electrically supervise these ball valves.


A pre-action trim 1/4 turn ball valve is shown below.  Ball valves should have signage, be sealed, chain/locked or electrically supervised:



Even this 1954 dry valve requires signage.


Dry pipe systems require air compressors (or shop air).  The compressors do not need to be electrically supervised nor do their valves require signage, chain locks or seals,  but they should.
Arrows point to two "weak" spots where this compressor's supply could be terminated, compromising the dry pipe system from staying "dry".  Both the outlet 1/4 turn ball vale and the electrical power switch appear to be closed/off.



Another photo of the compressor switch.  A sign or switch tamper lock is recommended.  This is a "weak" point in this system's design.


Pictured below is a quasi-tamper protected A/C power switch for another dry pipe system:


And with the cover open:


Recommend the 1/4 ball valve on the air compressor tank be sealed, chain locked or electrically supervised open.  See photo below:



Ideally the low air supervisory switch 1/4 turn ball valve (see arrow) should be sealed, chain locked or electrically supervised open.  There should be a sign, as well.  The all threaded rod supporting the riser is side loaded (non-axial load), this is design/install error (see red arrow), the riser clamp also appears to be poorly installed.


This next riser may have a missing ball valve handle (see arrow). The automatic ball drip appears to be rotated 90 degrees and may not readily discharge water into the funnel. Signage may be missing.



This dry valve's main control valve is closed and is it sealed in this position.  The dry system is out of service, likely due to a leak though that isn't noted.


This next dry valve is access-challenged.  The valve is located between a wall and the vertical risers in a busy pump room.


The placement of fire alarm junction box to support wiring for the butterfly control valve tamper switch is sub-optimally located.  The area immediate below the blue dry valve face plate is commonly doused in water during annual inspections of this valve.


Another example:





The dry valves below, impressively installed in a government building somewhere in eastern VA are subject to a manufacturer's technical service bulletin.




The following series of photos show a dry pipe valve as found upon arrival.  Note, the valve was not in a tripped state.


Another view:

Metal banding securing the riser mount air compressor may have failed.  Note, electrical cord that was used to hold compressor in place, this was removed during our service/call/visit. Air compressor weight is estimated from 30-50 pounds.


Shown below is another riser mounted air compressor with perhaps a better mounting design.

The photo below shows a Reliable Mode D 4" Dry valve with the face plate removed. An annual internal inspection is being conducted:

Below, a photo shows a drum drip (condensation trap) being serviced.  No signage is present:

Below, a photo of the internal chamber of a Multimatic A-4 pre-action valve undergoing inspection:

Two (2) photographs below show disassembled 3/4" ASCO brand 12W normally closed solenoid from multimatic A-4 pre-action valve.  Solenoid failed in open position immediately following testing.  Solenoid replaced, system returned to service.  No debris found.  Failure mode unknown.


Below, a Multimatic A-4 (trimmed as a pre-action) shown in the tripped configuration (following a test).  Also note evidence of a previous leak at the flange.


Following photo shows a Multimatic A-4 valve trimmed as a double interlock pre-action valve.  Arrow points to a 1/4 turn ball valve on the alarm line port.  1/4 turn ball valve should be sealed, chain locked or electrically supervised open.  Closure of this ball valve will result in no alarm signal being generated if main valve were to trip/activate due to fire.


Photo below shows a drain line for the charging line (downstream of solenoid) missing.  Solenoid was recently replaced (failed).  Also shown is some evidence of prior leak at the valve flange.

Photo below shows a Multimatic A-4 in test mode, with alarm test 1/4 turn ball valve open.

Photo below shows clapper in a Multimatic A-4 valve in reset position.

The photo below may show a valve with non-standard (read: customer/end user made) face plate gaskets.  A non-UL listed pressure gauge also appears to be installed:

Photo below may show a condensation trap/drum drip with foreign object attached.  There also appears to be no signage:

The following photograph shows a deluge valve trimmed as a pre-action valve.  Note the unsupervised alarm line 1/4 turn ball valve.  Accidental closure of this ball valve will result in no pressure (flow) alarm being sent.  There is also no signage.  Note the non-tamper screw (and non-manufacturer supplied) on the pressure switch.

The photo below shows partially installed screw in pressure switch, unlisted pressure gauge and unsupervised alarm line ball valve on a pre-action double interlock system.  There is also a small leak on the main drain valve (not pictured):

The following photo shows a pre-action riser with an incomplete drain.  The arrows point to a drain pipe that has to be manually fitted during any inspection/service work.  No permanent drain is available:






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