Filter Construction - std30200018

DOE-STD-3020-97

5.4

Filter Construction

Dimensions. The configuration and dimensions of open face

5.4.1

rectangular HEPA filters have been standardized and listed in Section

5.2.2, Table 1 of this standard. All other filter configurations are

considered "special" filters whose dimensions and tolerances must

be specified in the procurement documents. Dimensional tolerances

of "special" HEPA filters should conform to those specified in Section

5.4.3, Table 2 of this standard.

Filter Pack Construction. Filter packs shall be constructed of a

5.4.2

continuous sheet of filter medium which shall be pleated evenly to

form a pack or panel of equal depth throughout. The filter pack shall

be tight when tested according to the method described in Paragraph

8.1 of Institute of Environmental Sciences (IES) Document Number

IES-RP-CC-001.3. Repair of pin holes and other defects is not

acceptable.

Pleat and Separator Filters. Separators shall extend at

5.4.2.1

least 1/8 in. (3 mm) beyond the pleats of filter medium. The

plane formed by the edges of the separators shall be at

least 1/4 in. (6 mm) from the plane of the filter frame (less

gasket). The pleats shall be straight and shall not deviate

more than 1/2 in. (12 mm) from a line drawn from one end

of the pleat to the other end of the pleat and shall be

perpendicular to the filter case.

5.4.2.2

Mini-pleat filters. Filter medium panels shall be sealed in a

reservoir which is at least 1/16 in. (1.6 mm) deep. The

panels shall not vary more than 1/2 in. (12 mm) from a line

drawn from the top to the bottom of the panel and

perpendicular to the case. Filter medium support (ribbons,

strings, etc.) shall not vary more than 1/2 in (12 mm) from a

straight line drawn from top to bottom of the line formed by

the supports and shall be perpendicular to