Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
37 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
Piping must ensure ______ system ______ loss |
Minimum Capacity |
|
|
|
Rule 1: keep ______ size while maintaining ______ |
Smallest Velocity |
|
|
|
Rule 2: do not exceed _______ _______ |
Pressure drops |
|
|
|
Max allowable pressure drop across all systems in all conditions is |
2F |
|
|
|
Lower SST (sat suction temp)= |
Lower pressure drop |
|
|
|
High discharge temp = |
Higher pressure drop |
|
|
|
Condensing temp rises: |
Pressure drop rises |
|
|
|
Piping rules consist of minimizing (2) |
System capacity loss Refrigerant charge |
|
|
|
Piping must ensure: |
Oil returns to compressor |
|
|
|
Pressure drops depend on (2) |
Pipe diameter and length Number and type of fittings |
|
|
|
Asscessories installed in the line will effect the : |
Pressure drop |
|
|
|
Systems will perform more reliably by minimizing |
The refrigerant charge |
|
|
|
Using the _______ pipe diameter is necessary for high efficiency |
Smallest |
|
|
|
BCuP-6 is |
Copper to copper joints |
|
|
|
Code for copper to steel joints |
Bag-28 |
|
|
|
Where are K L and M wall thickness applications for pipe used |
K - c02 - thick L - refrig - medium M - plumbing - thin |
|
|
|
A p-trap is required where? At what height? |
any suction riser Greater than 8ft |
|
|
|
Any verticle line upward is considered a? |
Suction riser |
|
|
|
In long suction risers what should be used at what ft? |
P traps 30 ft |
|
|
|
If the suction line rises above the evaporator what should be installed? |
P traps |
|
|
|
Traps are not used with what refrigerant? |
410 |
|
|
|
Refrigerant lines should be |
Direct and straight between components |
|
|
|
Max velocity for suction, discharge and liquid lines are? |
4000 fpm 3500 fpm 350 fpm |
|
|
|
Min velocities for verticle rises are? |
1000fpm |
|
|
|
500 fpm is the min velocity for what? |
Horizontal risers |
|
|
|
Max pressure drop is |
2F / psi |
|
|
|
Double risers reduce ______ and maintain______ |
Load on the system And velocity for oil return |
|
|
|
Are double risers used in suction or discharge lines? |
Both |
|
|
|
Small pipe in double risers permits how many FPM at minimum load |
1000 fpm |
|
|
|
Bulbs in txv must be located before where? |
Equalizer |
|
|
|
Piping practice recommends long_____ but p traps must be |
90 elbows, short or street 90s |
|
|
|
Slope for refrig lines are? |
1/2" for every 10 ft |
|
|
|
Compressors above coils should use traps to? |
Stop from influencing txv bulbs |
Txv |
|
|
All piping features aiding in oil return can be eliminated with? |
Pump down systems |
|
|
|
Insulating condensate lines does 2 things? |
Prevents condensate Minimizes capacity loss to heat gain |
|
|
|
Suction line filters should be installed? |
Close to compressor |
|
|
|
Common insulation wall sizes are? |
3/8 1/2 7/8 |
|
