Ariz. Admin. Code § 11-1-1519

Current through Register Vol. 30, No. 50, December 13, 2024

Section R11-1-1519 - Unloading

A. Tank trucks will be visually inspected for leaks before they are allowed to enter the plant.

B. Unloading should be performed only during daylight hours. When it is necessary to unload at night, proper and adequate lighting should be provided around the tank truck and the working areas involved in the operation.

C. It is mandatory that the truck pad be arranged so liquid spillage will drain away from the truck and exposed structures. The pad will be of sufficient length to allow the truck and trailer a minimum of four-foot clearance at each end of two-foot clearance on each side. Because of the hazard of backing equipment into roadways and the possible need to move a truck quickly from the unloading place, it will be so arranged that the truck can be driven away in a forward direction.

D. Only qualified and properly instructed employees will operate the truck and make the hook-up of the hose from the tank truck to the receiving tank.

E. Before connecting for unloading, the truck engine will be stopped and not started again during the entire unloading operation until it is necessary to operate the pump by power take-off or to use the truck engine to operate compressors as a source of air for air pressure unloading.

F. Truck parking brakes will be set and, where necessary, the wheels blocked.

G. A sign will be placed at all areas where acid is loaded and unloaded, calling attention to the hazard.

H. Whether unloading by pump or air, the piping will, if possible, be arranged so the acid will drain toward the storage tank when the pump is shut down or when the discharge valve is closed.

I. When unloading line must be run across a walkway, suitable warning signs will be provided to denote the hazard.

J. Before starting to vent or connect, a water hose will be connected and ready for emergency use and the emergency shower and eye bath will be tested.

K. Wherever practicable, unloading will be accomplished by pumping. Whether pumping or unloading by air pressure, observe the following procedure:

1. Operate the relief valve to vent the tank.

2. Remove blind flange from air inlet line.

3. Leave this line open during pumping.

4. After making certain there is no air pressure, remove blind flange from standpipe and connect unloading line to standpipe.

L. If transfer is by means of air pressure, connect air line and apply air slowly until there is a normal flow of acid into the storage tank. Between the reducing valve and tank truck there shall be a safety valve set at not to exceed 25 lbs. pressure. If unloading by gravity, the reducing valve will be set at 10 lbs. pressure and at 20 lbs. pressure if not unloading by gravity. When the tank truck is empty, shut off the air and operate the relief valve to vent off the pressure. After pressure has been vented, disconnect the air line. Do not disconnect the acid unloading line until the tank truck is at atmospheric pressure and the tank truck standpipe drained. After disconnecting the acid unloading line, replace blind flanges on standpipe and air line.

M. Safety chains shall be used at all acid hose connections where the hose would whip if it came loose.

Ariz. Admin. Code § R11-1-1519

Former Rule 15:19.