Attachment 2 Pipe Drawing and Attachment 3 NAVSEA Pipe Standard.pdf

NAVAL SHIPS’ TECHNICAL MANUAL

CHAPTER 505

PIPING SYSTEMS

THIS CHAPTER SUPERSEDES CHAPTER 505 REVISION 4 DATED 15 JANUARY

2008.

DISTRIBUTION STATEMENT C: DISTRIBUTION AUTHORIZED TO GOVERNMENT AGENCIES AND THEIR CONTRACTORS: ADMINISTRATIVE AND OPERATIONAL USE (30 JANUARY 1995). OTHER REQUESTS

SHALL BE REFERRED TO THE NAVAL SEA SYSTEMS COMMAND (NSWCCD 9440).

WARNING: THIS DOCUMENT CONTAINS TECHNICAL DATA WHOSE EXPORT IS RESTRICTED BY THE

ARMS EXPORT CONTROL ACT (TITLE 22, U.S.C. SEC 2751, ET SEQ.) OR THE EXPORT ADMINISTRATION ACT OF 1979 (TITLE 50, U.S.C., APP 2401 ET SEQ.), AS AMENDED. VIOLATIONS OF THESE EXPORT LAWS ARE SUBJECT TO SEVERE CRIMINAL PENALTIES. DISSEMINATE IN ACCORDANCE WITH THE

PROVISIONS OF DOD DIRECTIVE 5230.25.

DESTRUCTION NOTICE: DESTROY BY ANY METHOD THAT WILL PREVENT DISCLOSURE OF CONTENTS

OR RECONSTRUCTION OF THE DOCUMENT.

S9086-RK-STM-010

REVISION 5

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PUBLISHED BY DIRECTION OF COMMANDER, NAVAL SEA SYSTEMS COMMAND.

*0910LP1116049* 1 APR 2013

505-4.8 HYDROBLAST CLEANING.

The most effective and the only NAVSEA approved method for cleaning calcium carbonate scale from col-lection, holding, and transfer piping is hydroblasting. Hydroblasting involves the use of a high-pressure waterjet machine which provides flow pressures of up to 10,000-pounds-per-square-inch gauge at the source. High-pressure water is introduced into the sewage lines through a flexible lance and nozzle. The impact of the water against the pipe interior pulverizes any scale or debris in the line. During this operation, the piping itself is not pressurized. By limiting the lance feed rate to one foot-per-minute, the pulverized scale is flushed from the sys-tem. This process requires cleaning out fittings at 50-foot intervals in the piping to minimize hydroblast pressure losses and maintain maximum cleaning effectiveness. Intermediate maintenance activities, tenders, shipyards, and other industrial activities including some private contractors have the capability to conduct hydroblast pipe clean-ing. To schedule system hydroblasting, OPNAV 4790/2K should be submitted to a Readiness Support Group or a Maintenance Control Center. This will ensure that hydroblast cleaning is properly scheduled and that the appropriate hydroblast planning document has been prepared.

505-4.9 COMBINING DRAINS.

Soil drains such as those from water closets and urinals may only be combined with drains from showers, lavatories, or sinks in close proximity to the diversion valve that directs the discharge overboard or to the pollu-tion control system (see NSTM Chapter 593, Pollution Control).

505-4.9.1 Do not connect waste pipes or drains from the following equipment directly to a plumbing drain unless an air gap is provided:

1. Refrigerator, steam table, or other receptacle where food is stored

2. Appliance, device, or apparatus used in the preparation of food or drink

3. Appliance, device, or apparatus using fresh water as a cooling or heating medium

4. Sterilizer, water still, fresh water treatment device, or potable-water-operated device.

505-4.10 PLUMBING VENTS.

All plumbing fixtures connected to the system shall have standard traps with water seals 2 to 4 inches deep.

Such traps shall be adequately vented to drain properly and to prevent siphoning of the traps. Each fixture trap shall be served by a vent located such that the total pitch of the fixture drain from the trap weir to the vent open-ing is not more than one inside diameter of the fixture drain pipe. Where a stack vent meets these requirements, individual back venting is not required.

505-4.10.1 The developed length of the fixture drain line between the trap weir and the vent connection shall not be less than 2 nor more than 48 pipe diameters. All vertical drains shall be stack-vented from the highest point.

Typical fixture piping and venting is indicated on NAVSHIPS DWG 810-1385920 through 810-1385923, inclu-sive.

505-4.10.2 High-velocity winds blowing into or across vent openings causes loss of seals or blowback of odors through traps because of the change in air pressure within the vents and plumbing system. This problem may be overcome almost completely by fitting half-round shields or tees at the open end of the vent. The run of the shields or tees shall be vertical rather than horizontal.

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505-4-10