Scott AP 75 Model 4.5
Scott AP 75 Model 4.5
General- AP 75 Model 4.5 NFPA 1981 approved (2007 standard)
Engines have 4 BA’s with 4 spare bottles
Engine 652 has 4 BA’s with 4 30 minute spare bottles
Truck 54 has 4 BA’s with 8 spares bottles
Truck 57 has 4 BA’s with 4 spare bottles
Medics have 2 BA’s with 2 spare bottles
RIT packs on Engines 52 and 56
Numbering system- ie 51-1, 51-2, 51-3
Backpack frame made up of metal frame with Kevlar and nomex straps/pads. Has built in Drag Rescue Loop for FF rescue. Tri-slide buckle to adjust for different bottles and cylinder latch with retention strap. Parachute style straps adjustable shoulder straps and breakaway Colorado belt by Fire Innovations . Pak alert sensor module is attached on either side of the bottle. Visual indicators on sensors with blue (during battery check)red (pre-alarm and alarm), green (sensing mode), and orange (low on air) lights. Takes 6 AA batteries and estimated life span of 6-9 months. Measures FF movement via small metal ball bearing that moves in slide to indicate movement. After PASS activated by either air being turned on or by using the PASS CONSOLE (personal alert safety system), Pak Alert will constantly sense movement. No movement for 20 seconds and PASS goes into pre-alert. If after 12 more seconds the pre-alarm is not cancelled by either moving lower body or by pressing the yellow button on Pass Console, the PASS goes into full alarm (95 dBa). When in full alarm, PASS sends out FF ID that can be located by the Pak Tracker.
The bottle is a 45 min bottle, holds 66 cubic ft of compressed air at 4500 PSI. Bottle made of aluminum core (70% of strength) wrapped by carbon fiber then layer of epoxy, fiber glass then layer of epoxy, then covered in durable gel coat (30% of strength). Bottle has cylinder pressure gauge, tri lobe hand wheel with ratchet design (2 ½ turns) to reduce possibility of accidently turning off bottle. Locking Tab. Burst disc set to 7200 PSI. 15 year life span with Hydro every 5 years.
From bottle connects to high-pressure line via the Compressed Gas Association CGA nut. AKA High Pressure Coupling. Stainless in 4500 PSI, Brass in 2216 and 3000 PSI. Nylon O-ring makes the connection air tight. Holes in threads to relieve pressure in case wrong size bottle is placed in incorrect SCBA.
From CGA into RIC UAC. Designed for emergency operation only. Includes the UAC PRV. PRV set to 4950 PSI.
Into pressure reducer. Redundant safety system with two interconnected pressure reducer valves. If first valve fails, air goes through the second valve and activates Vibra-alert. If both fail, they fail in the open position to allow air to flow rather than just shut off. Check secondary reducer by placing pen into hole in bottom off pressure reducer while breathing air.
From side of pressure reducer high pressure line (bottle pressure) to control PASS CONSOLE on right shoulder. Electrical runs from PASS module up to PASS CONSOLE also. Red button to manually activate PASS. Yellow button to reset or cancel alarm and to check unit by holding down for three seconds. LED lights remote gauge to see easier at night. Contains a photodiode to adjust HUD brightness. Must be within 10% of cylinder pressure.
From top of pressure reducer to low pressure line (about 100 PSI) through quick disconnect. Also has plug for HUD. If not aligned air will still flow but HUD will not function. From quick disconnect to secondary pressure regulator.
The regulator reduces the pressure from 100 PSI down to just over atmospheric pressure (14.7 + .5 ish). Air Saver Switch on top. Purge Valve at 9 o’clock. “Cherry on top…..1/4 turn”. Snap lock at 3 o’clock. Air comes through 9 top holes to decrease foggy masks (spray bar). Incorporates Vibra-alert system. Begins to vibrate at ¼ of bottle pressure approximately 1200 PSI and when first valve of pressure reducer fails. Uses compressed air from the bottle to activate (150PSI). Regulator locks into “puck” on waist belt.
HUD on regulator uses square lights to indicate level of air in bottle. Decreases Halo effect. 5 lights total. 1-4 indicate air ie. ¼ red light flashing, ½ yellow light flashing, ¾ one green light, full 2 green lights. Far right low battery warning that is red. When batteries become low the battery warning light will illuminate for 20 seconds then begin to flash slowly at once a second. Replace batteries ASAP.
Off of the left shoulder strap, the Dual EBSS (Emergency Breathing Support System) is mounted in a snap case. This is about 2 ft and has both male and female fittings on the end. This system can be used with another EBSS in low air situations or with the quick disconnect off the regulator in case of entanglement with scba. EBSS to be used with ONE person only.
Donning
Ensure all valves are closed and air saver switch on
Turn on bottle and listen for PASS to activate and check cylinder gauge for pressure
Don using coat method or over the head (coat method preferred due to weight)
Pull shoulder straps snug and connect waist belt and tighten. You want most of the weight on your hips
Ensure remote gauge matches the pressure of your cylinder gauge
Remove helmet and don face piece tightening from bottom to top
Ensure a good seal
Hood and helmet with helmet strap adjusted appropriately
2nd stage regulator fully clipped in and ensure purge valve is working appropriately…..Cherry on top, quarter turn
Don gloves and call time
