AASHTO (see note below)
Specific engineered load bearing measurement defined as follows:
16,000 lbs. over 8" x 20" area + 30% impact factor. (Note: American Association
of State Highway and Transportation Officials.)
AIRCRAFT LOAD HATCH
A hatch that is designed to withstand the extreme loading requirements of
aircraft runways, taxiways and other airside areas.
ANGLE FRAME
The basic frame is constructed out of angle lengths of metal. For aluminum
doors an extruded angle is used. For steel doors a structural angle is used.
Angle frame doors have an anchor flange along their base so that the frame will
be securely held in place when cast into concrete.
BASIN COVER
A metal plate (usually circular, but can be rectangular) that is bolted along a
small portion of its perimeter to the opening lip of a basin (or vault). The
remaining portion of the cover plate serves as a lid and opens 180 degrees.
BASIN COVER WITH INTEGRAL SINGLE DOOR
A metal plate (usually circular, but can be rectangular) that is bolted around
its perimeter to the opening lip of a basin (or vault). Within the metal plate
is a rectangular framed door to permit access into the basin.
CAST INTO CONCRETE
A hatch is "cast into concrete" when its frame is positioned over a vault and a
concrete slab is poured around it and allowed to set or harden.
CLEAR OPENING
The length and width dimensions measured in inches (or millimeters) of
unobstructed access through a hatch's frame. The clear opening "C" dimension
corresponds to the frame's span, and the clear opening "D" dimension
corresponds to the frame's length.
DIRECT TRAFFIC DOORS
Steel or stainless steel doors that are designed to support an AASHTO H-20
wheel load (16,000 pound over 8" x 20" area + 30% impact factor) in direct
traffic areas (e.g., roadways, on/off ramps, heavy traffic loading areas).
These type doors are designed to withstand the repeated impact caused by
continuous traffic.
EXISTING OPENING
An opening that already exists (e.g., a rectangular hole in cured concrete or
in a wooden floor).
FLOODTIGHT / GASTIGHT
A hatch frame with a built-in gasket that creates a flood tight/ gas tight seal
against the hatch cover when the door is in its closed position. This seal can
withstand the water pressure created by 25 feet of standing water (i.e., flood
conditions). The seal is also effective at preventing the passage of odors or
gases from the area below the door.
FLOODTIGHT RETROFIT
A hatch frame with a built-in rubber gasket that creates a Flood tight/ Gas
tight seal against the hatch cover when the door is in its closed position.
This seal can withstand the water pressure created by 10 feet of standing water
(i.e., flood conditions).
FRAME OPENING
The inside dimensions measured in inches (or millimeters) from the inside face
of the frame to the opposite inside face of both its short and long dimensions.
LOADING
The amount of weight a hatch cover can support - measured in either pounds per
square foot (p.s.f.) or pounds per square inch (p.s.i.).
METAL
USF Fabrication, Inc. uses a variety of metals including aluminum, steel and
stainless steel to manufacture hatches and miscellaneous products. Specific
metal alloys are available as per the customer's specification.
OCCASIONAL
TRAFFIC DOORS
Aluminum, steel or stainless steel doors that are designed to support an AASHTO
H-20 wheel load (16,000 pound over 8" x 20" area + 30% impact factor) on an
occasional basis (e.g., parking lots and off-street locations). These type
doors are not designed to withstand the repeated impact caused by continuous
traffic.
OVERALL SIZE
The outside dimension measured in inches (or millimeters) from opposite sides
of a hatch's frame. The overall width, or "E" dimension, corresponds to the
frame's span-Side A, and the overall length, or "F" dimension, corresponds to
the frame's length-Side B.
RECESSED
A hatch cover that is 1/8 inch lower than its surrounding frame. The particular
design allows tile or carpet to be glued to the cover and frame so that the
surface level of the tile or carpet on the door is flush with the surrounding
floor.
RETROFIT
To refit something (e.g., hatch) onto something else (e.g., an existing framed
hole) that already exists.
ROUND FRAME
The basic frame is constructed out of structural angles that are rolled into a
circle. Angle frame doors have an anchor flange along their base so that the
frame will be securely held in place when cast into concrete.
TROUGH
The basic frame is constructed so that a trough is created to channel water
towards a drain hole where it is discharged into a pipe. For aluminum doors the
trough frame is constructed of extruded material. For steel doors the trough
frame is constructed of structural shapes that are welded together. The trough
frame doors have an anchor flange along its base so that the frame will be
securely held in place when cast into concrete.
WATERTIGHT
Within the waste water industry the term "watertight" -- as pertaining to
access doors -- means that the door has a "drainable" frame commonly referred
to as a channel or trough or moat type frame. This type frame is designed to
collect water running off the cover so it can be directed to a drain and not
enter the vault area below the door.