Receiving and Storage > Hoses
Hoses used for loading or unloading ammonia into or from the refrigeration system have a limited life. The user must be alert to signs of hose deterioration before failure occurs. This page describes some inspection and testing procedures, work practices, and hose selection criteria to ensure the safe transfer of ammonia.
Figure 1. Unloading a railcar
- Hose failure, leading to a release of
- Provide information pertaining to the
hazards of ammonia to workers. [29 CFR 1910.119(d)(1)]
- Use hoses that are designed according to generally accepted good engineering practices.
[29 CFR 1910.119(d)(3)]
- Use hoses that are commonly used for
ammonia, such as:
- Stainless steel braided
- Nylon braided
- Use hoses that:
- Indicate suitability for ammonia.
- Have a working pressure of at least 350 psi and a burst pressure of at least 1750
- Mark at least every 5 feet the manufacturers name, the words Anhydrous Ammonia, the working pressure, and the year of manufacture.
- Make up hose assembly that is capable of withstanding a test pressure of 500
- Replace hoses according to the manufacturers recommendations.
- Do not use old, damaged, or mistreated hoses.
- Ensure employees are trained in the proper
care and maintenance of hoses. [29 CFR 1910.119(g)]
- Implement the following recommendations
for the use of hoses:
- Do not drag hoses over sharp or abrasive
surfaces, unless specifically designed for
- Protect hoses from severe end loads.
- Ensure the pressure in the hoses is at or
below its rated working pressure.
- Change pressure gradually to prevent
excessive surge pressures.
- Do not run over hose with equipment.
- Do not kink hoses.
- Use dollies to handle large size
- Storage of hoses
- Protect hose from:
- Extreme temperatures
- Too high or low humidity
- Corrosive liquids and fumes
- Radioactive materials
- Avoid stacking hoses in such a way
that the weight of the stack creates
distortions on the hose at the bottom.
- Store hoses in the original shipping
container if possible.
- Conduct routine inspections or testing for hoses as part of a Mechanical Integrity Program. [29 CFR 1910.119(j)]
- Inspect hoses and connectors prior to each
use. Look for:
- Loose covers
- Soft spots, which may indicate
broken or displaced reinforcement
- Perform a hydrostatic test periodically:
- Test for one minute at 150 percent of the
recommended working pressure.
- Test hoses when they are straight, not
coiled, or kinked.
- Flush hoses with alcohol to remove
traces of moisture.
- Never use a compressible gas for the
test due to the explosive action of
the hose should failure occur.
- Bleed air through an outlet valve
while filling it with the test medium.
- Place steel rods at ends and at
approximately 10 foot intervals to
prevent "whipping" should
- Bulwark the outlet end of the hose
to stop blown-out fittings.
- Protect testing personnel from the
forces of the testing media should
- Do not stand in front of or in back
of the ends of the hose being pressure
- Inspect the couplings or fittings.
- Specifications for Anhydrous Ammonia Hose,
7th Ed. Rubber Manufacturer's Association (RMA) Publication IP-14, (2003). Covers hose, three-inch inside diameter and smaller, commonly referred to as "pressure transfer hose", used to convey anhydrous ammonia liquid or to convey anhydrous ammonia gas where the gas is in contact with liquid ammonia.
- Safety Standard for Refrigeration Systems.
ANSI/ASHRAE 15-2001, (2001). This document specifies safe design, construction, installation and operation of refrigerating systems. This establishes safeguards for life, health and property and prescribes safety standards. This applies to new installations and modifications of existing installations. See the Table of Contents.
- Hose Technical Bulletin - Manual for Use, Maintenance, Testing, and Inspection
of Anhydrous Ammonia Hose, 4th Ed. Rubber Manufacturer's Association (RMA) Publication IP-11-2, (1997).
- A Guide for Developing a Training Program for Anhydrous Ammonia Workers. National
Institute for Occupational Safety and Health (NIOSH) Publication No. 79-119 (1978). Primarily emphasizes safety in the operation of facilities that handle anhydrous ammonia for agricultural purposes; however, the information included should interest all who handle anhydrous ammonia at other permanent installations. See the Table of Contents.