Installation of Gas Pipes

Installation, repair and replacement of gas piping or appliances shall be performed only by a qualified installing agency or gas fitter.

Protection of piping

Piping shall be buried to a sufficient depth or covered in a manner so as to protect the piping from physical damage. Measures should be taken to protect the piping from physical damage when it passes through flower beds, shrub beds and other such cultivated areas.

Protection against corrosion

Gas piping in contact with earth or other materials which will corrode the piping shall be protected against corrosion in an approved manner. When dissimilar metals are joined underground, an insulated coupling shall be used. Metallic piping shall not be laid in contact with cinder or ash.

Piping through foundation wall

Underground gas piping, when installed below grade through the outer foundation or basement wall of building, shall be either encased in a sleeve or otherwise protected against corrosion. The piping or sleeve shall be sealed at the foundation or basement wall to prevent entry of gas or water. 

Piping underground beneath buildings

If the laying of gas piping underground beneath buildings can not be avoided, the piping shall be encased in a conduit. The conduit shall extend into a normally usable and accessible portion of the building and, at the point where the conduit terminates in the building, the space between the conduit and the gas piping shall be sealed to prevent the entrance of gas from any possible leakage. The conduit shall extend at least 100 mm outside the building, be vented above grade to the outside and be installed in such a way as to prevent the entrance of water and moisture.

Building structure

The building shall not be weakened by the installation of any gas piping. Existing beams and joists shall not be cut or notched.

Piping supports

Gas piping in buildings, shall be supported with pipe hooks, metal pipe straps, bands or hangers of an approved type and material suitable for the size of piping, and located at specified intervals so that the piping cannot be moved accidentally from the installed position. Gas piping shall not be supported by other piping.

Piping entrance to buildings

When gas pipe enters a building through a wall or floor of masonry or concrete, it shall be sealed against the entrance of water, moisture or gas.

Piping in floors

Piping in solid floors, such as concrete, shall be laid in a channels in the floor suitably covered to provide access to the piping with a minimum damage to the building.

Changes in direction of gas pipe shall be made by the use of approved fittings, factory bends or field bends. Field bends shall be made by employing approved procedures and equipment.

Gas piping inside any building shall not be run in or through an air duct, chimney or gas vent, ventilation duct or elevator shaft. Gas piping shall not be taken through inaccessible or concealed areas where its condition cannot be inspected and accumulation of gas due to undetected leakage may create a dangerous condition.

Provides Drips Where Necessary

A drip shall be provided at any point in the line of pipe where condensate may collect. When condensation is excessive, a drip should be provided at the outlet of the meter. This drip should be so installed as to constitute a trap wherein an accumulation of condensate will shutoff the flow of gas before it will run back into the meter. All drips installed shall be readily accessible to permit cleaning, inspection or emptying. 

Cap All Outlets

Each outlet, including a valve or cock outlet, shall be firmly closed gas tight with a threaded plug or cap immediately after installation and shall be left closed until an appliance is connected thereto. Similarly, when an appliance is disconnected from an outlet and the outlet is not to be used again immediately, it shall be firmly closed gas-tight. The outlet shall be closed with tin caps, wooden plugs, corks or by other improvised means or objects. Use of a listed quick disconnect device is acceptable.

Prohibited Devices

Any device that will reduce the flow cross-sectional area or otherwise obstruct the free flow of gas shall not be inserted or placed inside the gas pipe or fittings.

Branch Pipe Connection

All branch pipe connections and outlets shall be taken from the top or sides of horizontal lines and not from the bottom.

Electrical Bonding and Grounding

The gas piping shall be electrically continuous throughout its length and earthed except in sections where cathodic protection system is used for protection against corrosion. The piping shall not be used to ground any electrical equipment.

Distance from Electrical Wiring

The distance between the gas piping and electrical wiring system shall be at least 60 mm. They shall be fixed to prevent contact due to movement. The gas piping should be installed below the electrical wiring. 

Distance from Stream piping

The gas piping and stream piping,if installed parallel, shall be at least 150 mm apart. The gas piping should preferably be installed below the steam piping. 

Gas piping to be Graded

All gas piping shall be graded not less than 1 in 750 to prevent accumulation of condensate or liquids in the line. All horizontal lines shall graded to risers, and from the risers, to the meter, or service regulator when there is no meter, or to the appliance.

The gas piping shall be painted red in order to differentiate it from other piping. Where the piping is exposed to sun rays, it shall be painted silver gray.

Documentation shall be maintained for all gas supply installations.

Ventilation Systems

Where required

Every space intended for human occupancy shall be provided with ventilation by natural or mechanical means during the periods when the room or space is occupied.

Natural ventilation

Sources

Natural ventilation of an occupied space shall be through windows, doors, louvers, skylights or other openings to the outdoor. Such ventilating openings shall open to the sky or a public street, space, alley, park, highway, yard, court, plaza or other approved space which comply with the requirements of the building code.

Area of ventilating openings

The minimum ventilating opening to the outdoors shall be 4% of the floor area being ventilated.

    Adjoining spaces

Where rooms and spaces without opening to the out doors are ventilated through an adjoining room, the unobstructed opening to the adjoining rooms shall be at least 8% of the floor area of the interior room or space, but not less than 2.33 m². The ventilation openings to the outdoors shall be based on the total floor area being ventilated.

    Opening below grade

Openings below grade shall be acceptable for natural ventilation provided the out side horizontal clear space measured perpendicular to the opening is one and one-half times the depth below the average adjoining grade.

Contaminants exhausted

Naturally ventilated spaces having contaminants present shall comply with the requirements of Mechanical exhaust will discuss later.

Lp-gas distribution facilities

Lp-gas distribution facilities shall be provided with air inlets and outlets arranged so that air movement across the floor of the facility will be uniform. The total area of both inlet and outlet openings shall be at least 0.7% of the floor area. The bottom of such openings shall not be more than 150 mm above the floor.

Design Considerations for Drainage and Sanitation System

Objective of design

For the design of drainage and sanitation system of different buildings according to building classification, the objective shall be to safeguard against fouling, deposit of solids and clogging and with adequate cleanouts and inspection chambers so arrange that the may be readily cleaned without the risk of health hazard.

a) The plumbing system shall be designed and adjusted to use the minimum quantity of water consistent with proper performance and cleaning.

b) Plumbing fixtures, devices and appurtenances shall be supplied with required volume of water at pressures adequate to enable these to function properly and without undue noise under normal conditions of use.

Different plumbing systems

For the design and installation for drainage piping, one of the following plumbing systems shall be used:

1) Single stack system,

2) One-pipe system, and

3) Two-pipe system.

1) A single stack system may be used with 100mm diameter stack foe buildings up to 5-storey height. The fixtures in each floor shall be connected to a single stack for increasing the rate of discharge in the downward direction. There shall be at least 200 mm vertical distance between the waste branch and the soil branch connection, while the soil pipe will be connected to stack above the waste pipe. The size of soil branch shall not be less than 100mm. The horizontal branch distance for fixtures from stack and bend(s) at the foot of stack to avoid back pressure as well as the vertical distance between the lowest connection and the invert of drain shall be shown in Fig -1. The recommended depth of water seal trap for different fixtures shall be in accordance with Table-1.

Lightning Protection of Buildings

Whether a building needs protection against lighting is matter of judgment on the part of designer; obviously it depends on the probability of a stroke and acceptable risk levels. For example, a higher risk is presumably acceptable for an isolated small bungalow than, say, for a children’s hospital. Whilst no exact rules can be laid down which would eliminate the designer’s judgment entirely, certain steps can be taken for an objective assessment of the risk and of the magnitude of the consequences. As an aid to making a judgment, a set of indices is given in table-1 and elaborated below for the various factors involved.

Usage of structure

The lightning hazard to human being within structure or a building is a very important in deciding how far to go in providing lightning protection. Schools, hospitals, auditoriums, railway stations etc., are places where a large number of people congregate and, therefore, would in general be structures of greater importance than small buildings and houses.

Type of construction

The type of construction of the structure has a large influence upon the extent of protection to be provided. A steel framed building to some extent is self-protecting and may not generally required additional protection, while brick buildings or buildings with thatched roof require greater degree of protection.

Contents or consequential effects

In addition to direct loss due to destruction of buildings by lightning, fire resulting from lightning, killing of livestock etc. there may be indirect losses which sometimes accompany the destruction of buildings and there contents. An interruption to business or to firming operations, especially at certain times of the year, may involve losses quite distinct form, and in addition to losses arising from the direct destruction of property. There are also cases where full community depends for safety and comfort in some respect on the integrity of a single structure, as for instance on the brick chimney of a water pumping plant. A lightning strike to it may have a serious consequence due to disruption of sanitary facilities, drinking water, water for irrigation, fire protection etc. the contents of buildings should also be considered as to whether they are replaceable, explosive, combustible, flammable vapor or explosive dust. These may present a hazard in a building that is otherwise immune to lightning. Contents like hay or cotton may make protection measures especially desirable.

Damage Repair of Ferrocement

Common types of damage

Ferrocement structures shall be inspected, as part of a regular maintenance programme, to detect any of the following types of damage. Appropriate repair measures shall than be taken.

Delaminations

Delaminations occur when ferrocement splits between layers in laminated constructions due to springing back or bridging of the mesh during construction. Delamination sometimes occurs at or near the neutral axis under impact or flexure when there are many voids in the interior layers. Such areas give of a hollow sound when taped with a hammer or stroked with a steel bar.

Spalls

A spall is defined as a depression resulting when a fragment is detached from a larger mass by a blow, by the action of weather, by pressure, or by expansion within the mass. Spalls shall be considered large when their size exceeds approximately 20 mm in depth or 150 mm in any dimension, and shall be repaired by replastering.

Spalls are usually caused by corrosion of steel, which causes an expansive pressure within the ferrocement. Chlorides in the concrete greatly increase the potential for corrosion of the steel. Under such conditions, continued spalling is lightly and the repair of local spalls areas may even promote the deterioration of the concrete because of the presence of dissimilar materials.

An area of steel corrosion and chloride contaminated concrete may be considerably larger than the area of spalled concrete, and the full area of contamination rather than the spall itself shall be Broken and replastered.

Fire damage
Ferrocement may be more susceptible to fire damage than conventional concrete because of thin cover.

If the fire were intense enough to release the amount of chemically bound water in the cement, destroy the bond between the cement and the aggregate, or oxidize the reinforcement, the surface would be charred and spalled so that the damage could be easily identified. Full scale removal and repair shall than be required.

Cracks and Local Fractures

Hairline cracks and crazing due to temperature changes or drying shrinkage in the cover coat do not require repair. Continuous wet curing will cause autogenous healing, and a flexible coating will conceal the crack from view. If cracks are caused by continuing overloads or are due to structural settlement and the cause cannot be removed, replacement or a structural overlay shall be required. Cracks due to occasional impact or overload may be repaired. Local fractures are cracks in which displacement of the section has occurred as a result of impact.

Evaluation of Damage

Evaluation of damage shall take into consideration its extent, cause, and likelihood of the cause still being active. The method of repair shall be dictated by the the type of damage, the availability of special equipment and repair materials, and the level of skill of the workers employed. Economic factors may influence the decision as to whether the repair shall be extensive and permanent, or limited in scope in response to an immediate problem.

Repair materials shall bond to the original structure, resist pollutions in the surrounding soil, water or air, and respond the same way to changes in temperature, moisture, and loads. Removal of deteriorated or chloride contaminated mortar trapped within the reinforcing mesh requires a large amount of hand labor, so it may be economical (and better for long term durability) to reconstruct or replace an entire area using the original structure as a form that can be left in place or removed after the overlaid structure has cured. Complete reconstruction shall be undertaken when chloride contamination, mesh corrosion, and deterioration of the mortar are extensive.

Testing for damage in ferrocement may be done by tapping with a hammer to break into any voids under the surface, or by drawing a metal bar over the surface and listening for sounds indicating voids or the presence deteriorated concrete. A high quality ferrocement should produce a bell like sound and resist moderately severe hammer blows without damage.

Surface Preparation for repair of damage

The primary adjective is to remove any deteriorated mortar or mortar contaminated with corrosive agents and to provide a surface to which the repair materials can be bonded properly. The rougher the surface, the greater the area available for bonding.

Removal of Deteriorated Concrete

As a first step in any repair or disintegrated, unsound, and contaminated mortar shall be removed. Saws and chipping hammers used for conventional concrete shall not be used for ferrocement unless large sections are to be completely removed.

Small areas shall be prepared by hand hammering just hard enough to pulverize deteriorated or cracked mortar, but not to the point of damaging the reinforcing mesh.

A pneumatic needle gun may be used for cleaning out broken ferrocement, opening out cracks and roughening the surface.

Particles of sound mortar embedded in the mesh need not be removed provided they are small enough not to interfere with the penetration of new mortar and they project from the finish surface.

Reinforcement

Any loose, scaly corrosion revealed on cleaning out the mortar shall be removed by sandblasting, water jet, air blasting, or vacuum methods.

An alternative method for removing rust is to brush naval jelly or spray dilute Phosphoric Acid over the repair area and flush thoroughly.

Where the mesh case has been displaced but is still intact, it may be pushed or jacked back in place and supported securely to withstand the pressure of applying the repair material. Where the reinforcement has been torn, the old mesh shall be laced back to close the opening.

When rods supporting the mesh is are torn they shall be spliced by a 15 diameter overlap of the partner rod or anchored by hooks.

Fire Protection Plumbing

Water required for interior fire protection

The minimum quantity of water for sprinkler and hose use within the building according to their occupancy classification shall be in accordance with table -1 indicating fire protection flow requirements or on the basis of the hydraulic design of the system.

Water source for fire protection 

Water required for interior fire protection of a building shall be supplied from one or a combination of the following sources:

Table-1 : Fire Protection Flow Requirements

Building Type	Sprinkler System (l/min)*	Standpipe and Hose system (l/min)*	Duration** (min)
Light hazard - I	1000	1000	30
Light hazard - II	1900	1900	50
Ordinary hazard - I	2650	1900	75
Ordinary hazard - II	3200	1900	75
Ordinary hazard - III	4800	1900	75
Notes: * Values will be for one riser serving floor area of 1000 m2. **These duration shall be for a building up to the height of 51 m. For greater height of 51-102 m and above 102 m, the duration will be 1.25 times and 1.5 tomes of the specified values respectively. Light hazard – I : Occupancy groups, A1, A2, A4 Light hazard – II : Occupancy groups, A3, A6, A8, B, C, D, E4, E7, F1 & F2 Ordinary hazard – I : Occupancy groups, E1, E3, E5, F3, F4, F5, F6, F7, G1 & G4 Ordinary hazard – II : Occupancy groups, G2 & H1 Ordinary hazard – III : Occupancy groups, G3 & H2 Extra hazard : Occupancy groups, j – pressure and flow requirement for this group shall be determined by Fire Department but shall not be less than required value for Ordinary hazard-III

Direct connection to water main

For continuous water supply (public water supply system or independent system only for fire protection) with sufficient quantity and pressure to feed fire fighting equipments during peak demand period, direct connection of the fire fighting system to the water main may be adopted (Fig-1).

Roof gravity tanks

For water supply system with inadequate quantity or pressure during peak demand period but with sufficient pressure to feed roof tank, a roof gravity tank shall be provided to feed fire fighting equipments(Fig-2).

Storage tank

For water supply system with inadequate pressure to feed fire fighting equipments or roof gravity tank, the building premises shall have a ground ( or under ground) tank to store water for fire fighting and one of the combination shown in Fig 3,4,5 shall be adopted.

The system only for fire fighting purpose may be designed with automatic fire pump as shown in Fig 3. The water supply system for domestic use and fire protection may be designed with roof gravity tank and manually controlled pump as shown in Fig 4. The pressure tank with automatic fire pump and the compressor may be used for supplying water to the fire fighting equipment as shown in Fig 5 and Fig 6. The location of the pressure tank shall be such that it will provide the required pressure at the highest fire fighting equipment.

The water stored in storage tank for fire fighting operation shall be used for other purposes ( see Fig-7).

The ground storage tank shall be easily accessible to fire engine of fire Department. In absence of space available for fire engine, the cover slab of ground storage tank shall be designed to withstand a vehicular load of local fire engine.

Individual Water sources

In absence of public water supply system, the building premises shall have individual water sources as specified in the post linked here. The individual water sources with adequate yield during peak demand period will serve as a fire service ground tank as shown in Fig-3, Fig-4, Fig-5. Otherwise, the water of the individual sources shall have to be stored in a tank as specified in storage tank section.

Design consideration for Standpipe and Hose System

1.The fire protection system shall be designed for their effective use either by amateur or trained fire fighting personnel or both.

2. All standpipes in standpipe system shall be sized so that they will provide a minimum flow specified in Table-1. In standpipe system with more than one standpipe, the supply piping shall be sized for the minimum flow specified in Table-1 for the first standpipe plus 1000 litre per minute for such additional standpipe. The total number of such additional standpipes shall not be more than 8. All standpipe risers shall be connected through a gate valve with a main of size equal to that of the largest riser.

3. The minimum pressure for standpipes supplying a 50 mm or larger hose shall be at least 300 Kpa. For standpipe supplying first aid hose (38 mm nominal) may have a minimum pressure of 200 Kpa.

4. The size (diameter) of stand pipes for various building height may be as shown in Table -2 or hydraulically designed to provide the required flow and pressure, stated above, at the topmost outlet.

Table-2 : Standpipe Sizes

No. of Storeys	Building Height(m)	Size of Stand pipe(mm)
Up to 5	UP to 17	75*
Up to 10	UP to 33	100
10 to 20	33 to 63	150
20to 54	63 to 65	200

*These pipe may be used only for occupancy groups A1, A2 and A4

5. The water supply required for combined system (for partial automatic sprinkler and Fire Department hose) shall be calculated in accordance with (2) above plus an amount equal to the hydraulically calculated sprinkler demand or 550 litre per minute for light hazard occupancy groups or 1900 litre per minute for ordinary hazard occupancy groups.

6. The size of combined system shall be at least 150 mm or hydraulically designed to provided the required flow (5) and pressure.

7. The standpipe shall be located in noncombustible enclosure such that it will be able to provide hose stream to the most remote area of the floor served.

8. The hose shall be connected to the standpipe within 1.5 m from the floor. Hose stations shall be easily accessible for inspection and testing.

Table-3 : Piping for Standpipe System

Materials	Standard
Copper Tube	ASTM B75, ASTM B88
Copper and Copper-Alloy Tube	ASTM B251
Steel Pipe	ASTM A55, ASTM A120, ASTM A135
Wrought Steel or Iron	ANSI B36.10

Table-4 : Standpipe Fittings

Materials	Standard
Cast Iron	ANSI 616.1, ANSI B 16.4
Copper	ANSI B16.18, ANSI B16.22
Malleable Iron	ANSI B16.3
Steel	ANSI B16.5, ANSI B16.9, ANSI B16.11, ANSI B16.25, ASTM A234

Occupancy Classification

Every building or portion thereof shall be classified according to its use or the character of occupancy as a building of occupancy A, B, C, D, E, F, G, H, J or k as defined below:

Occupancy A : Residential

Occupancy B : Educational

Occupancy C : Institutional

Occupancy D : Health Care

Occupancy E : Assembly

Occupancy F : Business and Mercantile

Occupancy G : Industrial

Occupancy H : Storage

Occupancy J : Hazardous

Occupancy K : Miscellaneous

Minor occupancy incidental to operations in another type of occupancy shall be considered as part of the main occupancy, and shall be classified under the occupancy group relevant for the main occupancy.

Any occupancy not mentioned specifically shall be classified by the authority under the occupancy group to which is use most closely resembles, considering the potential life and fire hazard.

Each occupancy group shall be sub divided as detailed in the following sections. The example provided for each occupancy group are nonexhaustive and indicative only. If there is any use or character of occupancy in a building which is not mentioned here, it shall be classified by the authority.

Occuoancy A : Residential

Buildings classified under this occupancy shall include all buildings that provide sleeping and living accommodations to related or unrelated groups of people, with or without cooking or dining facilities, except any building classified under occupancy C or D. This occupancy shall be subdivided as follows:

A 1 Detached single family dwelling

These shall include any building, detached from neighboring buildings by distances required by this Code, and having independent access, which is used for private dwelling by members of a single family.

Occuoancy B : Educational

Building classified under this occupancy shall include all buildings in which education and care are provided to children and adults. This occupancy shall be subdivided as follows:

B 1 Educational facilities

These shall include any building or portion thereof used for purposes involving assembly for instruction, education and recreation of more than six persons, and which is not covered by occupancy E, for example school, college, university class rooms, lobbies and related facilities, coaching centers, tutorial homes etc.