In installing j job manholes plug procedure

Non-dispersed mud is used to simulate the characteristics of clear water where clear water cannot be used for drilling for various reasons. The composition of the mud is water, bentonite, and polymers which are added to increase viscosity through flocculation or by viscosifying the water phase View Full Term.

By clicking sign up, you agree to receive emails from Trenchlesspedia and agree to our Terms of Use and Privacy Policy. A plug is a device that is inserted into a sewer line to temporarily restrict flow into predetermined areas. Blocking flow in a sewer pipe is necessary to perform maintenance and rehabilitation work on specific sections. Plugs are typically manufactured from rubber and can be procured in standard sizes or can be inflated with compressed air from an external source to fit the pipe diameter.

Plugs can be thought of as dams, which block the flow of water at specific pipe sections. They can be installed at two locations to block the upstream and downstream ends of the specific work location. Plugs are installed by creating an opening at the top of the pipe and inserting the plug at the given location s. Where entire dependence for emergency relief is placed upon pressure relieving devices, the total venting capacity of both normal and emergency vents shall be enough to prevent rupture of the shell or bottom of the tank if vertical, or of the shell or heads if horizontal.

If unstable liquids are stored, the effects of heat or gas resulting from polymerization, decomposition, condensation, or self-reactivity shall be taken into account. The total capacity of both normal and emergency venting devices shall be not less than that derived from Table F except as provided in paragraph i 2 v E or F of this section. Such device may be a self-closing manhole cover, or one using long bolts that permit the cover to lift under internal pressure, or an additional or larger relief valve or valves.

The wetted area of the tank shall be calculated on the basis of 55 percent of the total exposed area of a sphere or spheroid, 75 percent of the total exposed area of a horizontal tank and the first 30 feet 9. The flow capacity of tank venting devices 12 inches These flow tests may be conducted by the manufacturer if certified by a qualified impartial observer, or may be conducted by an outside agency.

The flow capacity of tank venting devices larger than 12 inches The tank shall be placed in the hole with care since dropping or rolling the tank into the hole can break a weld, puncture or damage the tank, or scrape off the protective coating of coated tanks.

Tanks shall be covered with a minimum of 2 feet 0. When underground tanks are, or are likely to be, subject to traffic, they shall be protected against damage from vehicles passing over them by at least 3 feet 0. When asphaltic or reinforced concrete paving is used as part of the protection, it shall extend at least 1 foot 0.

Size of vents. Each tank shall be vented through piping adequate in size to prevent blow-back of vapor or liquid at the fill opening while the tank is being filled. Vents shall discharge vapors outside the buildings. Tank supports shall be of concrete, masonry, or protected steel. Single wood timber supports not cribbing laid horizontally may be used for outside aboveground tanks if not more than 12 inches Water spray protection or its equivalent may be used in lieu of fire-resistive materials to protect supports.

Tank foundations shall be designed to minimize the possibility of uneven settling of the tank and to minimize corrosion in any part of the tank resting on the foundation. In addition to the preceding requirements, each tank so located that more than 70 percent, but less than percent, of its allowable liquid storage capacity will be submerged at the established maximum flood stage, shall be safeguarded by one of the following methods: Tank shall be raised, or its height shall be increased, until its top extends above the maximum flood stage a distance equivalent to 30 percent or more of its allowable liquid storage capacity: "Provided, however," That the submerged part of the tank shall not exceed two and one-half times the diameter.

Or, as an alternative to the foregoing, adequate noncombustible structural guides, designed to permit the tank to float vertically without loss of product, shall be provided. Sources of ignition may include open flames, lightning, smoking, cutting and welding, hot surfaces, frictional heat, sparks static, electrical, and mechanical , spontaneous ignition, chemical and physical-chemical reactions, and radiant heat. Tanks not marked in accordance with the above codes shall be strength tested before they are placed in service in accordance with good engineering principles and reference shall be made to the sections on testing in the codes listed in paragraphs i 1 iii A , iv B , or v B of this section.

Except for underground tanks, this tightness test shall be made at operating pressure with air, inert gas, or water prior to placing the tank in service. In the case of field-erected tanks the strength test may be considered to be the test for tank tightness. Underground tanks and piping, before being covered, enclosed, or placed in use, shall be tested for tightness hydrostatically, or with air pressure at not less than 3 pounds per square inch Mechanical caulking is not permitted for correcting leaks in welded tanks except pinhole leaks in the roof.

Conformity with the applicable provisions of Pressure Piping, ANSI B31 series and the provisions of this paragraph, shall be considered prima facie evidence of compliance with the foregoing provisions. Material other than steel, nodular iron, or malleable iron shall be designed to specifications embodying principles recognized as good engineering practices for the material used. If such materials are used in above ground piping systems or inside buildings, they shall be suitably protected against fire exposure or so located that any spill resulting from the failure of these materials could not unduly expose persons, important buildings or structures or can be readily controlled by remote valves.

Welded or screwed joints or approved connectors shall be used. Threaded joints and connections shall be made up tight with a suitable lubricant or piping compound. Pipe joints dependent upon the friction characteristics of combustible materials for mechanical continuity of piping shall not be used inside buildings. They may be used outside of buildings above or below ground. If used above ground, the piping shall either be secured to prevent disengagement at the fitting or the piping system shall be so designed that any spill resulting from such disengagement could not unduly expose persons, important buildings or structures, and could be readily controlled by remote valves.

The drawing shall contain all the piping and equipment in the area for which it is prepared. On the plot plan the piping routing is sketched free hand before beginning the drawings. The rack is sketched first. Then the lines from racks to equipment are drawn based on the best layout of lines.

Manhole steps, if required, shall be cast in place units consisting of steel rebar construction covered with polyvinyl material and specifically manufactured for use in manhole installation. Sewer laterals, unless otherwise noted, shall consist of service wye, lateral pipe, plug, and cleanout as indicated on the drawings.

Provide approved 'Fernco' or other fittings for connections to existing services where required. Gate valves shall be resilient seat non-rising stem valves meeting the following requirements:. Plugs shall be cast iron encapsulated with Buna-N rubber. Valve shall be provided with stainless steel seats and thrust collar. Sizes up to 12" shall be designed for psi.

Larger sizes shall be designed for minimum psi. Shall be provided with brass inlet gate valve to allow isolation of unit, and shall be provided with backflush ports, valves and hose assembly. Verify installation or connection requirements prior to construction by potholing as necessary. Verify that Work covered under other sections of these specifications is complete to the point that Work covered under this section may properly commence without hindering or damaging Work of other trades.

Do not proceed with construction until unsatisfactory conditions have been corrected. Install sewer piping to the lines, grades, and elevations indicated on the drawings. Install service wyes at the locations indicate or as otherwise required to provide service connections to existing services. Bedding shall be prepared in accordance with Section of these specifications and as indicated on the drawings.

Overexcavate as necessary and install approved material to provide firm, stable foundation for sewer piping installation. Overexcavation shall be approved by Engineer.

Prepare bedding to insure trench bottom is free of large stones, debris, frozen, organic or other deleterious materials. Excavate to pipe bells to insure pipe is supported properly along its entire length. Dewater trench as necessary to prevent the accumulation of groundwater or other unacceptable water in trench. Pipe laying operations shall proceed in a uphill direction with all bell facing uphill unless otherwise specifically approved by Engineer.

Contractor shall follow pipe manufacturer's recommended practice for lowering, assembling, and installing sewer pipe. During pipe installation, verify that no foreign material is inside pipe. Clean interior of each pipe joint prior to installation.

Sewer pipe shall be laid to uniform line and grade between manholes unless otherwise approved by the Engineer. Plug open end of installed sewer piping and close trench at the end of each day's work. Open trenches may not be left overnight without specific permission from the Engineer. Sewer mains shall be installed beneath water mains wherever possible.

If vertical separation or installation beneath water main requirement can not be met, provide ductile iron sewer piping for a distance of not less than 10 feet on either side of the crossing. Pipe joints shall be located to provide maximum distance from water mains.

Advise Engineer of vertical separation less than 18" and receive approval of corrective measures prior to proceeding with sewer main installation. If 12" vertical separation can not be provided, encase sewer main in concrete for a distance of not less that 10 feet on either side of crossing. Maintain a minimum 10' horizontal separation between sewer main and existing water mains wherever possible.

Provide ductile iron sewer piping for sections where 10' horizontal separation is not possible. Advise Engineer of horizontal separation less that 10' and receive approval of corrective measures prior to proceeding with sewer main installation. Install backfill and compact in accordance with manufacturer's requirements and as indicated on the drawings.

Backfill shall not be placed in lifts greater than can be properly compacted to the required density. Backfill material shall be free of large rocks, organic or frozen material. Excavation, bedding and backfill for manhole installation shall be in accordance with Section of these specifications and as indicated on the drawings.

Install manholes at locations and to grades indicated on the drawings. Set manhole lid flush with finished surface unless otherwise noted on the drawings. Cast-in-place base and floor shall conform with requirements of standard details for layout and configuration. Prevent debris from entering installed sewer main piping via manholes by providing suitable barriers or covers. Pipe transition into manhole must be smooth and free of any pockets or indentations.