ABYC SYSTEMS CERTIFICATION EXAM REVIEW UPDATED ACTUAL
QUESTIONS AND CORRECT ANSWERS VERIFIED 2027 EDITION
1. What is the most often used materials for potable water systems?
Polyethylene
2. Name 5 materials allowable for contact use in potable water systems:
1. Copper Alloys (incl. bronze, brass and nickel-copper) 2. AISI Type 300 series stainless steel 3. Glass-lined
metal 4. FDA approved plastic 5. FDA approved rubber
3. What device can be used to separate potable water from other water systems?
Siphon Break
4. What is the device used to maintain a stable pressure and minimize pump cycling, and where
should it be located?
Accumulator Tank, after pump/filter and before check-valve
5. At what what percentage of nominal working pressure shall the relief valve be set?
175%
6. Is a standard household type relief valve acceptable for hot water tanks?
No, typically these are too high (up to 400% of nominal pressure)
7. For the pressure reducing valve and check valve installed after a shore water connection, what is
the maximum allowable pressure?
nominal working pressure, not to exceed 80 PSI
8. Where shall the storage tank be vented?
overboard
9. What is the maximum allowable pressure to which the storage tank and vent system be subjected?
3 PSI or mnfg's maximum, which ever is greater.
10. What temperate range is required for pumps to be able to tolerate exposure?
-40 °F to +140 °F
11. When operating at an ambient temperature of 140 F, what is the max allowable surface
temperature of a pump?
257 F
12. Potable water systems must be equipped with a drain. T or F?
True
13. Storage tank inlet may also serve as the tank vent. T or F?
False
14. Storage tank inlet caps must be retained to prevent loss. T or F?
True
15. Storage tanks must be equipped with a vent. T or F?
True
1
,16. Storage tank vent may be used for filling purposes. T or F?
True
17. What rate of static pressure must a storage tank withstand?
At least 1.5X the pressure exerted by the distance from the tank bottom to the deck fill plate or vent, but
not less than 3 PSI.
18. What is the max pressure that a desalinator can impart to a storage tank?
3 PSI
19. Each desalinator must be equipped with an automatic shutoff salinity detector. T or F?
True
20. What marking must be on pipe or tubes that are not capable of handling hot water?
"For Cold Water Use Only"
21. What is the test pressure for water heater tank 15 gal or less? over 15 gal but under 120 gal?
125 PSI, 300 PSI
22. What is the max pressure relief valve setting for hot water tanks?
175 PSI
23. What is the max temperature relief setting for hot water tanks?
210 F
24. What is the max allowable water output temperature for hot water system?
125 F
25. All potable water system connections shall be positioned above the normal bilge water
accumulation level. T or F?
True
26. Exposed metallic parts of a potable water system shall have provisions for electrical bonding. T or
F?
True
27. For what reason might a holding tank collapse during pump-out?
Improper venting
28. What type of MSD (Marine Sanitation Device) discharges effluent with fecal coliform bacteria
count <= 1,000 (per 100 ml) and no suspended solids?
Type I
29. What type of MSD (Marine Sanitation Device) discharges effluent with fecal coliform bacteria
count <= 200 (per 100 ml) and <= 150 mg suspended solids per liter?
Type II
30. What type of MSD (Marine Sanitation Device) is designed to hold sewage or any waste derived
from sewage?
Type III
2
, 31. What is the name given to the complete system including toilets, hoses, pipes, holding tanks and
fittings designed to receive, retain, vent and pump out sewage?
Retention System
32. What is the name of the system that includes all sanitation equipment and fittings designed to
receive, treat, vent and discharge sewage?
Treatment System
33. What is another name for a vented loop that prevents back siphoning by breaking suction yet
allowing normal flow when pressurized?
Siphon break
34. When calculating holding tank size, how many flushes per day are included in the calculation?
5
35. What volume of human waste is used per flush when calculating holding tank size?
0.14 gallons
36. True or False: If a portable toilet is secured and fitted with a deck pump-out fitting and vent it
qualifies as a type III device.
True
37. Why must careful consideration be given to the location and routing of inlet and discharge lines
for manual flush toilets when the "shut-off" merely bleeds air into the inlet line?
Prevention of siphoning
38. When and why must siphon breaks be installed in a sewage system?
Whenever components are installed below the max heeled water line - to prevent back flow into the vessel
or unintentional siphoning of untreated effluent overboard.
39. A seacock may be installed instead of a siphon break to prevent discharge and back siphoning. T
or F?
True
40. What special provision must be included for a sewage y-valve when the discharge seacock is not
lockable?
The handle must be lockable in the direction of the holding tank
41. Name four ways to separate a fresh water flushing system from potable water system.
Air Gap, Vacuum Break, Double Check Valve, Dedicated Water Tank
42. What is the minimum hose ID for use on un-macerated sewage?
1.5 inches
43. What provisions should be made if using rigid PVC for sewage?
Secure mounting to minimize vibration effect, use flexible hose to connect to fitting and hull.
44. What plastic material is recommended for sewage holding tanks?
linear or cross-linked polyethylene, 1/4 inch thick or greater.
45. Of the three major type of Fiberglass Reinforced Plastic (FRP), which one is not recommended and
why?
Epoxy and Vinyl Esther are ok, but polyester resin is not because of susceptibility to osmotic blistering.
3
QUESTIONS AND CORRECT ANSWERS VERIFIED 2027 EDITION
1. What is the most often used materials for potable water systems?
Polyethylene
2. Name 5 materials allowable for contact use in potable water systems:
1. Copper Alloys (incl. bronze, brass and nickel-copper) 2. AISI Type 300 series stainless steel 3. Glass-lined
metal 4. FDA approved plastic 5. FDA approved rubber
3. What device can be used to separate potable water from other water systems?
Siphon Break
4. What is the device used to maintain a stable pressure and minimize pump cycling, and where
should it be located?
Accumulator Tank, after pump/filter and before check-valve
5. At what what percentage of nominal working pressure shall the relief valve be set?
175%
6. Is a standard household type relief valve acceptable for hot water tanks?
No, typically these are too high (up to 400% of nominal pressure)
7. For the pressure reducing valve and check valve installed after a shore water connection, what is
the maximum allowable pressure?
nominal working pressure, not to exceed 80 PSI
8. Where shall the storage tank be vented?
overboard
9. What is the maximum allowable pressure to which the storage tank and vent system be subjected?
3 PSI or mnfg's maximum, which ever is greater.
10. What temperate range is required for pumps to be able to tolerate exposure?
-40 °F to +140 °F
11. When operating at an ambient temperature of 140 F, what is the max allowable surface
temperature of a pump?
257 F
12. Potable water systems must be equipped with a drain. T or F?
True
13. Storage tank inlet may also serve as the tank vent. T or F?
False
14. Storage tank inlet caps must be retained to prevent loss. T or F?
True
15. Storage tanks must be equipped with a vent. T or F?
True
1
,16. Storage tank vent may be used for filling purposes. T or F?
True
17. What rate of static pressure must a storage tank withstand?
At least 1.5X the pressure exerted by the distance from the tank bottom to the deck fill plate or vent, but
not less than 3 PSI.
18. What is the max pressure that a desalinator can impart to a storage tank?
3 PSI
19. Each desalinator must be equipped with an automatic shutoff salinity detector. T or F?
True
20. What marking must be on pipe or tubes that are not capable of handling hot water?
"For Cold Water Use Only"
21. What is the test pressure for water heater tank 15 gal or less? over 15 gal but under 120 gal?
125 PSI, 300 PSI
22. What is the max pressure relief valve setting for hot water tanks?
175 PSI
23. What is the max temperature relief setting for hot water tanks?
210 F
24. What is the max allowable water output temperature for hot water system?
125 F
25. All potable water system connections shall be positioned above the normal bilge water
accumulation level. T or F?
True
26. Exposed metallic parts of a potable water system shall have provisions for electrical bonding. T or
F?
True
27. For what reason might a holding tank collapse during pump-out?
Improper venting
28. What type of MSD (Marine Sanitation Device) discharges effluent with fecal coliform bacteria
count <= 1,000 (per 100 ml) and no suspended solids?
Type I
29. What type of MSD (Marine Sanitation Device) discharges effluent with fecal coliform bacteria
count <= 200 (per 100 ml) and <= 150 mg suspended solids per liter?
Type II
30. What type of MSD (Marine Sanitation Device) is designed to hold sewage or any waste derived
from sewage?
Type III
2
, 31. What is the name given to the complete system including toilets, hoses, pipes, holding tanks and
fittings designed to receive, retain, vent and pump out sewage?
Retention System
32. What is the name of the system that includes all sanitation equipment and fittings designed to
receive, treat, vent and discharge sewage?
Treatment System
33. What is another name for a vented loop that prevents back siphoning by breaking suction yet
allowing normal flow when pressurized?
Siphon break
34. When calculating holding tank size, how many flushes per day are included in the calculation?
5
35. What volume of human waste is used per flush when calculating holding tank size?
0.14 gallons
36. True or False: If a portable toilet is secured and fitted with a deck pump-out fitting and vent it
qualifies as a type III device.
True
37. Why must careful consideration be given to the location and routing of inlet and discharge lines
for manual flush toilets when the "shut-off" merely bleeds air into the inlet line?
Prevention of siphoning
38. When and why must siphon breaks be installed in a sewage system?
Whenever components are installed below the max heeled water line - to prevent back flow into the vessel
or unintentional siphoning of untreated effluent overboard.
39. A seacock may be installed instead of a siphon break to prevent discharge and back siphoning. T
or F?
True
40. What special provision must be included for a sewage y-valve when the discharge seacock is not
lockable?
The handle must be lockable in the direction of the holding tank
41. Name four ways to separate a fresh water flushing system from potable water system.
Air Gap, Vacuum Break, Double Check Valve, Dedicated Water Tank
42. What is the minimum hose ID for use on un-macerated sewage?
1.5 inches
43. What provisions should be made if using rigid PVC for sewage?
Secure mounting to minimize vibration effect, use flexible hose to connect to fitting and hull.
44. What plastic material is recommended for sewage holding tanks?
linear or cross-linked polyethylene, 1/4 inch thick or greater.
45. Of the three major type of Fiberglass Reinforced Plastic (FRP), which one is not recommended and
why?
Epoxy and Vinyl Esther are ok, but polyester resin is not because of susceptibility to osmotic blistering.
3
