The mobile fill station shall have the capacity for filling two (2) SCBA/SCUBA cylinders simultaneously or separately. The enclosure shall be designed to contain the impact of suddenly expanded high pressure air and all displaced fragments in the unlikely event of a cylinder or fill component rupture. The containment design shall feature a loading door that is trapped inside the fill enclosure cabinet frame when closed. The enclosure shall include an automatic, safety interlock to prevent filling unless the loading door is completely in the closed position and a safety relief valve to protect operators in the event that the SCBA/SCUBA fill pressure exceeds 4750 PSIG.

The external construction of the high pressure, breathing air fill station shall be appliance-like; using formed, fabricated steel structures and panels without visible welds, burrs or grinding marks.

II. SCBA Fill Enclosure and Access Door Control

The fill station must allow the complete fill process to be accomplished from the front and include an access door control that enhances the enclosure containment design, is simple to operate and requires minimal physical operator effort. Two (2) fill whips, each fitted with a cylinder fill adapter, shut-off valve and pressure bleed valve shall be located within the enclosure.

The access door assembly shall include two (2) integral, steel cylinder sleeves to secure the SCBA/SCUBA cylinders while being filled. The assembly shall tilt forward until horizontal, positioning the cylinder sleeves at the optimal height for loading and unloading cylinders with minimal operator effort.

The access door control shall include an air actuator handle designed to operate a pneumatic cylinder to open and close the access door. For opening, the handle shall lower the access door, releasing it from behind the cabinet frame and allowing the operator to pull the door forward to load and unload SCBA/SCUBA cylinders. For closing, the access door is rotated up to the vertical position and the handle shall then raise and trap it behind the cabinet frame. When fully raised, the door trips the safety interlock allowing air to flow to the fill station.

The access door shall be supported on the enclosure frame with an adjustable bearing bushing on each side assuring a balanced, smooth rotation and effortless operation when opening and closing. A gas strut shall secure the assembly to the enclosure so that it does not require operator support when opening or closing and to cushion the access door landing when opened.

III. SCBA Cylinder Fill Enclosure Flow Control System

The SCBA cylinder fill enclosure shall be tied in to the existing air flow controls.

The SCBA/SCUBA cylinder fill control system shall include an air control panel with all components, devices and piping arrangement necessary to direct compressed high pressure breathing air to the SCBA/SCUBA cylinders being filled. (A)

The SCBA/SCUBA cylinder fill control system shall include a regulated air control panel with all components, devices and piping arrangement necessary to direct supplied compressed high pressure breathing air to the SCBA/SCUBA cylinders being filled. Additionally, an inlet CGA connection and flow valve shall be provided to direct high pressure breathing air from an external source to the air storage system.. (B)

A cascade control system shall be included for the number of banks specified below. The cascade control system shall permit filling or drawing down each air storage cylinder, independently of each other, while filling SCBA/SCUBA cylinders. An air storage by-pass valve shall be included to permit filling SCBA/SCUBA cylinders through the storage fill inlet or directly from the compressor. (C)

The control system shall include a dual regulator package for safely filling SCBA/SCUBA cylinders with two (2) different pre-set pressures. The package shall include installation of the standard and an additional regulator behind the panel at pre-set pressures. A selector button located at the control panel shall be required to select air flow from the regulator with the highest pre-set pressure. A pneumatic actuator valve shall return the air flow to the low pressure regulator after every high pressure fill cycle. (D)

An additional "dedicated fill circuit" shall be included to safely fill SCBA/SCUBA cylinders at a different pressure than that flowing from the main control panel regulator(s). The "dedicated fill circuit" shall include an adjustable, pre-set regulator installed behind the control panel plumbed directly to a dedicated fill whip and adapter located in the fill enclosure and a separate panel mounted flow valve and gauge. (E)

All air flow components and indicators must be labeled and mounted on a steel control panel located above the fill enclosure. (A, B, C and D)

The panel shall be painted in a matte shade with a textured finish to eliminate glare and enhance the visibility of gauges and indicators. The control panel shall be illuminated. The panel shall be designed so that it can slide forward, out of the compartment, and tipped down so that all piping and components are accessible for maintenance.

As a minimum, the air control panel must include the following:

Inlet pressure gauge. (A)
SCBA/SCUBA cylinder(s) fill control valve. (A)
SCBA/SCUBA cylinder(s) fill pressure gauge. (A)
Panel lights on/off switch. (A)
Adjustable, 0-6000 PSI self-relieving regulator. (B)
Regulator outlet pressure gauge. (B)
Air storage fill, CGA inlet fitting and flow control valve. (B)
Two (2) bank cascade control with a single valve and gauge per bank. (C)
Three (3) bank cascade control with a single valve and gauge per bank. (C)
Four (4) bank cascade control with a single valve and gauge per bank. (C)
Two (2) bank cascade control with “To” and “FROM” valves and gauge per bank. (C)
Three (3) bank cascade control with “To” and “FROM” valves and gauge per bank. (C)
Four (4) bank cascade control with “To” and “FROM” valves and gauge per bank. (C)
Air storage by-pass valve. (C)
Dual regulator high pressure selector button. (D)
“Dedicated fill circuit” flow valve and gauge. (E)