Figure 6-20. Emergency vent installed

TM 5-5430-209-12

(1) Place assembled ladder where it is convenient

(2) Starting at the third hole from either end of the

to the pressure vacuum valve (8, fig. 6-19) at the outer

sections, place ladder steps (3) underneath the sections

perimeter of the deck.

with step angles all facing in the same direction. Aline

(2) Lift the ladder and set end bolt holes of braces

the steps between sections, and install 1/2 by 1-inch

(5 and 6) over bolts in bottom chime of the staves.

bolts (4) through sections and steps from the top side.

Mark the bolts.

Install a nut on each bolt and tighten securely.

(3) Set bolt holes of handrails (7) over bolts in the

(3) Refer to figure 6-19 and install brace (5) on

top chime of the staves. Mark the bolts.

bottom of right section (1) with the 3-hole side of the

(4) Remove nuts from the marked bolts and set

brace facing the section. Use bolt (4) and nut, but do

ladder in place over the bolts. Install nuts and tighten

not tighten. Install brace (6) on left section in the same

them securely.

manner.

(5) Tighten nuts securing braces (5 and 6) to

(4) Install handrail (7) on the top outside face of

sections (1 and 2).

each section. Secure each handrail with two bolts (4)

6-17. Emergency Vent

and nuts.

c. Installation.

a. General. The emergency vent (1, fig. 6-20) is

NOTE

installed on the manhole dome (2) of petroleum storage

Use a temporary ladder where applicable when

tanks to provide a means of venting the tanks, when

installing the access ladder.

necessary. It consists of a cast steel body (3) and a cast

steel cover (4) equipped with a lifting handle. The cover

is hinged to the body.

ME 5430-209-12/6-20

Figure 6-20. Emergency vent installed.

b. Installation. Emergency vent (1, fig. 6-20)

(2) Install emergency vent (1, fig. 6-20) over the sket

3places manhole cover (3, fig. 6-18).

and bolts in manhole dome (2). Install nuts fig. 6-18)

(1) Remove nuts (4) and manhole cover (3).

on the bolts and tighten securely.

6-22