Prohibition collection
in air conditioning and plumbing facility
for Beginner Engineers

NPO (Nonprofit Organization)
Society for the Study of Mechanical Service System

Prohibition collection Contents
Piping (common)

Piping line order

Piping (common)

Vertical piping distance

Piping (common)

Common base for parallel piping

Piping (common)

Prohibition of T shaped piping

Piping (common)

How to use eccentric reducer

Piping (common)

Prohibition of round shaped nipple

Piping (common)

Avoiding up and down piping

Piping (common)

Shrine gate shaped piping

Piping (common)

How to make branch piping (1)Piping (common)

How to make branch piping (2)Piping (common)

Installation of safety valve discharging outlet

Piping (common)

Steam supply piping around control valve

Piping (common)

Fixing point for expansion and shrinkage piping

Piping (common)

Piping lining block needed for wall mounted fixture

Piping (common)

Prohibition of in-beam piping

Piping (common)

Keeping margin around branch piping

Piping (common)

Piping arrangement around equipment

Piping (common)

Attention for drain-up piping

Piping (common)

Making drain piping downward near equipment

Piping (common)

Connection of drain pipe for air handling unit and others

Piping (common)

Limitation for piping passing through receiving tank room

Piping (common)

Piping passing through building expansion part

Piping (common)

Counter measure of ground subsidence for piping passing through building entering part

Piping (common)

Horizontal piping for lifted water

Piping (common)

Drain valve for fire department connection pipe

Drainage piping

Inclination for drainage pipe

Drainage piping

Drainage pipe in lowest floor

Drainage piping

How to connect drainage horizontal pipeDrainage piping

How to connect with drainage horizontal pipeDrainage piping

Pipe diameter of horizontal piping

Drainage piping

Connection between vertical piping and horizontal piping

Drainage piping

Installation location for cleanout

Drainage piping

Displacement for drainage cleanout

Drainage piping

Installation of flexible joint (socket fitting) - vertical pipe -Drainage piping

Installation of flexible joint (socket fitting) - horizontal pipe -Drainage piping

Prohibition of double trap

Drainage piping

Step for outdoor drain pit (concrete made)Drainage piping

Drain pit size

Drainage piping

Combined flow for outdoor rainwater drain

Drainage piping

Drainage in lower place than surrounding ground

Drainage piping

How to install drain valve

Drainage piping

Air break for indirect drain

Drainage piping

Making lead pipe length 1m or less

Drainage piping

Using cast iron pipe as standard length pipe

Drainage piping

Inflow pipe to soil water tank

Vent piping

Underfloor vent piping

Vent piping

How to branch vent pipe

Vent piping

Connection with vent vertical pipe

Vent piping

Prohibition of up and down vent piping

Vent piping

Vent pipe for soil water tank

Vent piping

Opening location for vent pipe

Vent piping

How to make vent pipe for oil tank upward

Piping accessories Installing valves in easy-to-operate place
Piping accessories Installing valves in easy-to-maintain place
Piping accessories Sluice valve direction
Piping accessories Attention for butterfly valve installation
Piping accessories Installing butterfly valve
Piping accessories Check valve for lifted water pump

Piping accessories Installation order for valves
Piping accessories Valve for hot water piping
Piping accessories Place needing flexible joint
Piping accessories Place needing vibration isolation joint
Piping accessories How to use flexible joint
Piping accessories Flexible joint and support base around tank
Piping accessories Installation for piping accessory
Piping accessories Space needed for Y shaped strainer bottom
Piping accessories How to install pressure gauge
Duct

Elbow inner diameter

Duct

Branch after elbow

Duct

Location and direction for damper before branch

Duct

Installation direction for damper in fan delivery side

Duct

Installation for damper around fan

Duct

Delivery side duct for fan

Duct

Duct bending in fan delivery side (1)Duct

Duct bending in fan delivery side (2)Duct

Suction side duct for fan

Duct

Installation location for air volume control unit

Duct

Installation for air volume test port

Duct

Duct bending around coil and filter

DuctHopper spreading and narrowing

Duct

Installation direction for exhaust smoke outlet

Duct

Displacement for sound absorption elbow and damper

Duct

Connection with mixing air chamber

Duct

Duct connection with louver chamber and vent cap

Duct

Duct connection with common exhaust air louver

Duct

Location for outdoor inlet and exhaust air louverDuct

Air inlet installation for down offset ceilingDuct

Air outlet installation near floor surfaceDuctCeiling air inlet

Duct

Attention for deciding duct routeDuct

Connection for ventilation duct in car parking

Equipment

Avoiding dead water for receiving tank

Equipment

Insect protection net and bird protection net

Equipment

Piping around receiving tank

Equipment

Water supply by direct connection pressurization pumpEquipment

Drain and air purge around equipment

Equipment

Maintenance valve around equipment

Equipment

Connection pipe diameter for equipment

Equipment

Connection pipe diameter for pumpEquipment

Suction side connection diameter for pump (1)Equipment

Suction side connection diameter for pump (2)Equipment

Installation location for lined pumpEquipment

Lined pump support - floor mounted -Equipment

Lined pump support - ceiling mounted -Equipment

How to make piping around header

Equipment

Installation for 2 or more cooling tower

Equipment

Distance between cooling tower and opening

Equipment

Displacement of outdoor unit for packaged air conditioner

Equipment

Location of air inlet and air outlet for total heat exchanger

Equipment

How to select fan

OthersInstallation of suction pit for fire extinguishing tank

OthersInstallation location for laundry machine pan

Building facility system terminology

Piping (common)

How to make branch piping (2)In case of the branch from horizontal steam piping, the branch should be upward. And, the steampiping should have forward (steam flow direction) down inclination in order to drain the condensed water.

Bad caselta
zon

ri

Hotal

onzori

H

inma

inmae

pip

Branchpipee

piptalonzoriH(in case of downward piping)

inmae

pip

(in case of upward piping)

Good case

ri

Hoain

lmta
zon

chranBzonri
HoainmtalepipBranchpipeepiphanc

ipep(in case of downward piping)

Brtalzonri
Ho18inmae

pipepip(in case of upward piping)

Valve for hot water piping

Piping accessories

Do not use the stop valve (globe valve) for hot water supply. Install the gate valve (sluice valve)in which the air pocket occurs hardly. (The hot water has a lot of dissolved oxygen. And the dissolved
oxygen separates into water easily. As result, the air pocket is generated in the pipe.)

Bad case

Globe valve

Air stays easilyHot water supply pipe

Good caseSluice valve

Hot water supply pipe

68

Elbow inner diameter

Duct

The Elbow inner radius should be 1/2 or more duct width W. In case of not keeping 1/2 or more W, theguide vane and other airflow smoothing device should be installed. (Depending on the specification, thestandard may be 1 W.)

Bad case

Good case76

Avoiding dead water for receiving tank

Equipment

In case the water inlet and outlet of the receiving tank are located near, all water does not always flow,
and it tends to be the dead water. Therefore, the water inlet and outlet should be located as opposite aspossible.

Bad case

ManholeWater inlet

Water level
regulating valve

Water flow

It tends to be the deadwater.

Water outlet

Good case
Water level
regulating valve

Water inlet
ManholeWater flow

Water outlet

100