No_5_February_1964 — Page 99

In a typical ward 12 oxygen and suction points serve the treatment room and 25 of the 31 beds.

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manifold room The external manifold large enough to house two battery sets of sixteen 240 cubic foot oxygen cylinders and one set of 20 3,600 gallon nitrous oxide cylinders and to allow for a liquid oxygen conversion installation at a later date with the prospect of financial econo- my in consumption costs. Vacuum insulated equipment is under con- sideration for this purpose.

Safety warning devices are con- nected to the telephone operator's room and the maintenance engineer's office to show when pressures or sup- plies are running dangerously low. The systems have been designed to give continuous services to 30% of the total number of outlets simul- taneously.

Oxygen outlets (720 approx.) are supplied at 45 lbs per square inch pressure and the annual demand is expected to be about 500.000 cubic feet.

Nitrous oxide is piped to each operating theatre outlet at 32 lbs per square inch pressure and the annual demand is expected to be about 800.000 gallons. Over 50 points are provided.

Vacuum pressures of up to 25" of mercury are being provided at about 800 outlets and standby pumps are included in the systems.

Compressed air is also included to meet medical requirements at almost 100 points in addition to operating the pneumatic airconditioning plant controls throughout the Hospital. The three air compressors are each capable of producing pressures of 100 lbs per square inch through duplicated air receivers and air filters.

In operating theatres, special over- head swinging booms have been de- signed to reduce the nuisance of sup ply tubes trailing on the floors which have also special anti-static proper- ties to reduce any anaesthetic gas ex- plosion risks.

In general, horizontal basement or lower ground floor ring mains serve the risers which are either enclosed in corridor cupboard ducts or con- cealed in wood wool structural lin- ings to columns or walls. It is thought that this is probably one of

the largest hospital installations in the world. Standard British oxygen equipment is being used throughout the Hospital.

(E) Plumbing Services

A total of over 30 miles of pipes are involved and these pipes vary in size from 18 inch cast iron down to half inch copper.

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The general basis of the design is that the supply services pumped up to the tower roof level tanks and then distributed within the roof level crawlway by ring mains to the vertical drops, off which the

individual rooms at each floor are supplied. Waste and other ser- vices as required drop down in cor- ridor ducts to the basement where connections are made to the large horizontal mains or pipes.

As far as possible all pipes in rooms have been concealed in horizontal window cill level ducts and in corridor cupboards which house the vertical drops for some rooms involving more than ten pipes.

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In order to reduce any inconveni- ence from possible break-downs and repairs, each fitting has cut off valves and as far as possible pumps, tanks and the main feed pipes have been duplicated by means of ring mains with cross connections and suitable cut off valves.

The Hospital is served by gravity from eight inch mains from a ser- vice reservoir about 500 yards to the Northwest.

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In addition an alternative or serve supply can be taken from mains on the Southwest of the site and between them a continuous 24 hour full supply can be maintained for the exclusive use of the Hospital.

The lower half of the building is supplied by gravity from the higher level service reservoir nearby. The upper floors are supplied from high level roof tanks which basement level duplicated pumps will keep full.

If necessary the lower floors can also be supplied from roof tanks.

The design has been based on an anticipated demand of up to 100 gallons for each of 1300 patients per day and a peak demand of one

THE HONG KONG & FAR EAST BUIIDER — VOLUME 18, NUMBER 5

third of the daily total between 8 and 10 a.m.

Basement and roof tanks hold about 20,000 and 30,000 gallons re- spectively and two 25 h.p. pumps each with standbys can each deliver about 200 gallons a minute to the roof level. The two towers have plumbing ring main interconnections at basement and roof level.

The system has been designed for a daily consumption of up to 35 gal. lons at 150°F. for each of 1300 patients and a peak load in 2 hours of one third of about 14,000 gallons.

The calorifiers are as follows:

2 Nos. 4'0" dia. x 8'3" long each having storage capacity 600 gal. lons and heating unit to raise 7000 gallons of water from 50 to 150°F. in 1 hour.

2 Nos. 3'0" dia. x 7'0" long each having storage capacity 300 gal- lons and heating unit to raise 3000 gallons of water from 50 to 150°F. in 1 hour.

The steam demand for this service may be as high as 23,000 lbs per hour.

FLUSHING WATER

A six inch branch pipe is taken from the 15 inch main sea water dis- charge after it has been used for cooling the airconditioning condens- ing turbines.

Tower roof level tanks of 30.000 gallon capacity are supplied from basement tanks of 20,000 gallons by two 25 h.p. pumps each of which have standbys and are capable of pumping up about 200 gallons per minute.

The basement and roof level tanks are intercommected, the latter by ring mains. It has been anticipated that approx. 80,000 gallons-just over 60 gallons per patient--will be required per day.

Instantaneous flush type valves have generally been used on all sluice fittings throughout the Hospital and owing to the specially corrosive nature of the harbour sea water the internal plumbing has normally been carried out in P.V.C. pipes. All the quarters are also supplied with sea water for flushing from these base- ment tanks.

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