Code of Colorado Regulations
1200 - Department of Agriculture
1202 - Inspection and Consumer Services Division
8 CCR 1202-5 - STORAGE AND HANDLING OF ANHYDROUS AMMONIA
Appendix B - TFI-RMA SPECIFICATION FOR ANHYDROUS AMMONIA HOSE TFI-RMA STANDARD NO. M-5

Current through Register Vol. 47, No. 17, September 10, 2024

1. SCOPE

This specification covers hose and hose assemblies 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. This specification primarily covers hose and hose assemblies which have a minimum burst pressure of 1750 psig, a safety factor of 5, and a maximum working pressure of 350 psig. These figures should not be misconstrued to mean that they are the maximum pressures to which anhydrous ammonia hose and hose assemblies are built, since higher pressure hose and hose assemblies are available for special applications.

2. SIZES AND TOLERANCES

Anhydrous ammonia hose shall be made with the following dimensions and tolerances:

* The O.D. dimension and tolerance were intentionally omitted from this tabulation to provide for developments in both hose and couplings.

3. CONSTRUCTION

3.1 Inner Tube

The tube shall be uniform in quality and thickness and free from injurious defects. It shall meet the physical requirements of Section 4. The material shall be resistant to hardening or other deterioration due to the action of ammonia.

3.2 Reinforcement

The reinforcement shall consist of any material not adversely affected by permeating ammonia. The reinforcement shall be applied evenly and uniformly, and in such a way that it will meet the physical requirements of Section 4. In constructions utilizing a ply or plies of wire reinforcement, the composition of the wire shall be a suitable corrosion resistant stainless steel.

3.3 Cover

A rubber cover if used shall be uniform in quality and thickness and free from injurious defects. It shall meet the physical requirements of Section 4. The cover shall be so compounded or constructed that it will not blister in service, and will be resistant to deterioration due to the action of ammonia. A gas tight cover shall be pricked to relieve pressure build-up between inner tube and cover. The cover shall be resistant to deterioration due to exposure to the elements.

4. PHYSICAL TESTS

4.1 Tension Test of Tube and Cover

4.2 Adhesion Test

4.2.1 In constructions having braided wire or woven wire filler reinforcing members, only the cover adhesion requirement will apply, as it is impractical to prepare adhesion test specimens except for determining cover adhesion.

4.3 Burst Test

All sizes have a minimum burst of 1750 psig. (See Scope).

4.4 Ammonia Performance Test

During the conditioning and flexing described in Sections 7.4 and 7.4.2 there shall be no evidence of cover blistering or leakage. At the conclusion of the conditioning and at the conclusion of the flexing test, the burst must still meet the requirements of Section 4.3 . There shall be no evidence of separation of the component parts when the remainder of the samples are examined.

4.5 Low Temperature Test

The hose shall not fail at minus 40ºF plus or minus 2°, when tested as described in Section 7.5, of this Specification.

5. TYPES OF TESTS

5.1 Acceptance Inspection

This includes all the tests specified, with the exception of the ammonia performance test.

5.2 Qualification Tests

The qualification tests are intended to establish that the hose is properly designed and constructed to give satisfactory service life. These tests shall be conducted by a recognized independent laboratory. The qualification tests shall consist of all the tests specified herein including the ammonia performance test.

6. METHOD OF SAMPLING

6.1 Acceptance Inspection

A 24-inch sample of each size and type hose, representative of the lot, shall be selected from each lot manufactured at one time, or from each 25,000 feet, whichever is smaller.

6.2 Qualification Test

In addition to the samples specified in Section 6.1, two 12-foot lengths of each size hose shall be selected for the ammonia performance test. Each new hose shall be subjected to a qualification test, and again whenever there has been a design change.

7. METHODS OF TESTING

7.1 Tension Test of Tube and Rubber Cover

The tension test shall be made in accordance with ASTM D-380.

7.2 Friction Test

The friction test shall be made in accordance with ASTM D-380.

7.3 Burst Test

The burst test shall be made in accordance with ASTM D-380 using the method entitled "Straight Bursting Test"

7.4 Ammonia Performance Test

Two 12-foot lengths of hose, to be marked "A" and "B", shall be filled with liquid anhydrous ammonia by connecting to a tank and flushing out with ammonia to remove all the air. One end of each length shall be sealed and the other end left connected to the liquid space of a tank of anhydrous ammonia. The hose shall then be conditioned for 14 days at ambient temperature of 60º to 100ºF. A valve between the ammonia tank and the hose may be closed providing it is opened at least once each day to completely fill the hose with liquid anhydrous ammonia. The hose shall be examined each day for visible defects. There shall be no evidence of the cover blistering or perceptible leakage. If the hose is valved off at each end when liquid full, a hydrostatic relief valve should be provided between the block valves.

7.4.1 Conditioned Hose Burst Test

A 24-inch sample cut from hose marked "A" shall be subjected to a straight hydrostatic bursting test in accordance with Section 7.3.

7.4.2 Conditioned Hose Flexing Test

7.4.2.1 The 12-foot hose length marked "B" shall be installed in flexing test machine (Fig. 1). One end of the hose is to be connected to the traveling block and the free end passed around two pulleys with diameters as shown in Table 1. A 30-pound weight shall then be attached to the free end.

7.4.2.2 From the remainder of hose length marked "A", (sizes 1 inch and under only), cut a section to length indicated in Table 1. Connect one end to the vertically traveling block as shown in Fig. 1 and connect the other end to the liquid space of a tank of anhydrous ammonia. Maintain the temperature of hose and ammonia between 70ºF and 90ºF. The test on the feeder hose does not apply to sizes over 1 inch. To conduct the flex test on the larger sizes any convenient hose may be used as a feeder hose.

7.4.2.3 The flexing test shall continue for 72 hours at a rate of approximately 470 cycles per hour with a 42-inch vertical movement of the traveling block. A valve between the ammonia tank and the hose may be closed providing it is opened at least once each day to pressurize the hose. The hose shall be examined each day for visible defect. There shall be no evidence of cover blistering or leakage.

7.4.2.4 At the conclusion of the flexing period, cut a 24-inch sample from hose "A" and from hose "B" and subject each sample to a straight burst test in accordance with Section 7.3. All samples shall have a minimum burst of 1750 psig.

7.5 Low Temperature Test

A straight piece of hose at least 24 inches long, conditioned to minus 40ºF plus or minus 2ºF for 5 hours, and bent 180° within two seconds around a mandrel 12 times the nominal inside diameter of the hose, shall not break or show cracks in the tube or cover.

8. RETESTS AND REJECTIONS

Any hose which fails in one or more tests may be resampled and retested, for which purpose two additional samples shall be selected from the hose for the test that failed to meet the requirements. Failure of either of the retested samples shall be cause for final rejection.

9. HOSE ASSEMBLIES

The couplings must be so designed and constructed that an assembly shall have sufficient strength that it will reach the minimum burst pressure, as required by Section 4.3 , before the end fittings leak or come off when pressure is applied as specified in ASTM D-380 for Hydrostatic Tests. Fittings must be resistant to the action of anhydrous and aqueous ammonia and in no case may assemblies be supplied with copper alloy fittings.

10. MARKINGS

Hose shall be clearly marked at least once every five feet with manufacturer's name or trademark, "Anhydrous Ammonia," the maximum working pressure in psig, year of manufacture, and "TFI-RMA Spec.," for all hose manufactured after January 1, 1964. As indicated in the Scope, the maximum working pressure must not be less than 350 psig.

11. PACKAGING

11.1 Packing

Unless otherwise specified, hose shall be packed in substantial commercial containers of the type, size and kind commonly used for the purpose, so constructed as to insure acceptance and safe delivery to common or other carriers, at the lowest rate, to the point of delivery specified on the order.

11.2 Identification

Unless otherwise specified, shipping containers shall be marked with the size and quantity of hose therein, the name of the manufacturer and the number of the order.