Sounding tubes may be fabricated from 1 ½ NPS or larger. Only when otherwise specified, Schedule 40 components, manufactured from the list of material indicated in Practice F 1155 and Specification A 53/A 53M, Grade S or Grade ERW. In addition, sounding tubes may be fabricated in stainless steel for stainless steel tanks.

5.1.1 Sounding tubes passing through or terminating in fuel tanks, potable water tanks, or clean salt water ballast tanks should be constructed of 70-30 copper nickel, but other suitable material is acceptable.

Striker plates shall be fabricated in accordance with Specification A 36/A 36M.

The fittings shall be designed in accordance with ANSI B16.5, B16.9, B16.28, or B16.11 as applicable (See Table 21 in Practice F 1155), and the installation shall be in accordance with ANSI B31.1 as modified by Specification F 722. These standards cover the fitting tolerances.

Some cargo may preclude the use of materials specified in this guide. However, configuration examples are applicable for all applications.

When a sounding tube is combined with the air escape, either three 1¼-in. (approximately 30-mm) diameter holes approximately 12 in. (305 mm) from the tank top equally spaced or six ½-in. (approximately 15-mm) diameter holes approximately 6 in. (150 mm) from the tank top equally spaced can be used for perforations. See Fig. 2.

Figs. 1-4 are guidance details.

FIG. 1 Type I Sounding Tube

FIG. 2 Type II Sounding Tube

FIG. 3 Type III Sounding Tube

FIG. 4 Type IV Sounding Tube

1.1 This guide covers design and construction criteria for striker plates and sounding tubes, excluding deck penetrations and caps, for use with sounding rods or tapes in freshwater, saltwater, and oil tanks.

1.2 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.