Piping Ppt Flashcards
Types of refrigeration and air conditioning tubing:
K - ______duty ( _____ wall)
L - ______ wall thickness
M - ______ duty (____ wall)
Type __ is most common in this trade
K - heavy duty (thicker wall)
L - Regular wall thickness
M - Light duty (thin wall)
Type L is most common
Which Refrigeration piping is the most crucial to install correctly?
Suction line
Pressure Drop in piping is controlled by the following: (4)
- pipe _______
- pipe ______
- number of _________
- fluid ________
- Pipe Diameter
- Pipe length
- number of fittings
- fluid velocity
Suction line design and installation:
Common goal limit suction line to __F equivalent pressure drop
2F
Suction line design and installation:
- Return ___ back to the compressor under all load conditions
- Prevent oil from draining from active and inactive _________
- Prevent liquid refrigerant from draining back to the _________ during the off cycle
- Prevent unnecessary _____ gains and the line sweating
- oil
- evaporator
- compressor
- heat gains
Suction line design and installation:
- Ensure minimum gas velocity ___fpm from horizontal runs
- Ensure minimum gas velocity of ____fpm from vertical risers (travelling up)
- Ensure max velocity of ____fpm is not exceeded
- Ensure trap is installed at the base of all suction line risers over __ft (good up to 25ft of rise)
- 500fpm
- 1000fpm
- 4000fpm
- 8ft
Suction line design and installation:
- Use double suction risers if system can reduce capacity down to ___% of full load
- Insure high compression ratios are _______
- Pitch horizontal runs 1/2” down every ___ft in direction of flow
- Use _____ at the top of coil when pump down control is not used
- 50%
- avoided
- 10ft
- loops
Suction line design and installation:
Ensure ___” of suction line within the conditioned space before exiting
18”
Hot gas line design and installation:
Common goals limit hot gas line to __F equivalent pressure drop
2F
Hot gas line design and installation: Goals:
- Ensure oil leaving the compressor travels to the _________
- Avoid _________
- Use proper ________ devices
- Prevent refrigerant migrating back to the compressor during ____ cycles
- condenser
- trapping
- vibration
- off cycles
Hot gas line design and installation:
- Ensure minimum gas velocity of ____fpm for horizontal runs
- Ensure minimum gas velocity of ______ fpm for verticals risers
- Trap at base of all hot gas risers over 8ft (good up to ___ft)
- 500
- 1000
- 25ft
If vertical velocity is less than 1000fpm then a double ______ should be installed
riser
Hot gas design and installation:
- Use double hot gas risers if system capacity drops to ___% of full load
- Ensure a max gas velocity of _____fpm is not exceeded
- pitch all horizontal runs 1/2” every 10ft in direction of _____
- 50%
- 4000fpm
- flow
Hot gas line design and installation:
- Ensure compression ratios are kept to a ________
- Avoid ____ heading of the common discharge when using multiple compressors as it causes excessive noise, vibration, excessive pressure drops
- minimum
2. bull
Liquid line design and installation:
Common goal limit liquid line to __F equivalent pressure drop
2F
Liquid line design and installation:
- Ensure flash gas is not created because of excessive ______ drops
- Flash gas can cause reduced _______, noisy _______ device, unstable metering device operation
- pressure
2. capacity, metering
Liquid Line design and installation:
- Run lines as _____ as possible
- No _____ required on vertical risers
- Ensure pressure drop of 2F is not ________
- Max liquid velocity ____fpm avoiding liquid hammering
- direct
- traps
- exceeded
- 360fpm
Oil equalization multi-compressor installations:
Methods:
1. Oil separator with oil reservoir and float ______
- Oil equalization (one line _____, one line ______)
- switch
2. above, below
Risers that have an eight foot vertical rise or less do not need to have an ___ ____ at the bottom of the riser
oil trap
- If the rise of the discharge or suction riser is greater than eight feet then a ____ should be installed at the bottom of the rise
- The reason for this is so that oil will not accumulate at the heads of the compressor during the ____cycle
- trap
- off
2. off
Evaporator Condensate Drain Line:
- This line is normally 3/4” but may be other sizes due to different ___________
- This line is trapped to ______ un-conditioned air from infiltrating the space
- Good piping practice dictates the trap is normally installed _______ the controlled space
- manufacturers
- prevent
- outside
Purpose of a pump down system?
prevent liquid refrigerant from migrating back to the compressor
