АлександрД
Contributor
some years ago I collected facts about different behavior of Intermediate pressue gauge (IPG) due to regulator tests. Here is original topic on Russian language.
Below I will put automated translation with small corrections. Can somebody (from moderators) make language correction for better understanding?
All written below is just my experience, and following then you make at your own risk!
FAULT DIAGNOSTICS OF 1st (regulator) AND 2nd (demand valve) STAGES
for a better understanding of the following article, it is recommended to familiarize yourself with what is generally a 1st and 2nd stages, and how it works, namely: Scuba Traveller How a Scuba Diving Regulator's First Stage Works Qdivers Doha | PADI scuba diving courses and more in Qatar
There are a number of simple procedures that can be used to check the correctness of 1st, 2nd and the pressure gauge, which can be carried out without any additional equipment.
All these procedures are detailed in many sources, and they are not discussed here. As part of this instruction, it is the option that is considered when you have a pressure gauge for checking the intermediate pressure, and if you have it, you do a full cycle of checking everything you can.
There are those that are screwed directly into the LP port (Low Pressure), there are those that are connected to the expansion hose of the compensator / BSD (usually under the INTL 8 mm nozzle), which are put in the hose break 2nd (before demand valve) and are often supplemented with adjustment for the adjustment of the 2nd seat .
we connect the pressure gauge (intermediate pressure)
at the same time if you know for sure that there is some problem, and there is time to do it - then it is better to leave connected to 1st (to the 1st stage) by minimizing the hoses, and as short as possible.
at the very minimum - it's only a hose to 2nd. If the manometer in the variant for connection to the hose connection of the BSD - then the BSD hose is still needed.
it is necessary that the pressure gauge (high pressure) should remain in place.
If you check the assembled state of the "spider" (1st with 2nd assembled), without removing the excess hoses, this basically does not change anything, but it will not make it easy to identify some of the problems.
we connect the regulator (1st + 2nd + hoses + pressure gauges) to the cylinder in which at least the pressure of 100 atm ...
(this is the case if the balanced diaphragm 1st is checked, but if it is piston, then it can and will work at 100bar, give 200 can make pssst, the cause is mainly o-ring piston-scraped, scratched. Therefore it is highly desirable to check full pressure)
1) open the cylinder. slow. till the end. the HP pressure gauge quickly showed the pressure in the tank, the IP manometer abruptly jumped by an amount of about 8.5-10.5 atm and froze, and does not move further on a half-bar. - already good.
2) pressed strongly for 1 second and sharply released the button 2nd. if the manometer IP jumped down no more than 1 atm, then returned exactly to the same value (8.5-10.5) and froze in place, and the manometer HP almost did not flinch (ie notice it didn't get a chance) - all is well - the regulator is OK (within the scope of the check). (some sets of 1st-2nd can show a greater fall, it is generally not very good, but it is probably a feature of the work of a particular model, so it can not be unequivocally said that this is a critical malfunction)
(* 1) to the set pressure. As standard, the factory settings of most gear units specify an installation pressure of 9.5-10 atm. Some scuba divers can change it for themselves, or when servicing it they can be rebuilt for colder water (6.5-8.5) or for easier breathing (10.5-11, but with reconfiguration and a 2nd). There are also non-standard 1sts (for example old Soviet ones from 5 to 6.5 atm or Divex, or some type of Poseidon - 11 atm), but still the overwhelming majority of the widely used 1stes operate in the range from 9 to 10.5 atm.
now what can be faulty and how it looks:
Below I will put automated translation with small corrections. Can somebody (from moderators) make language correction for better understanding?
All written below is just my experience, and following then you make at your own risk!
FAULT DIAGNOSTICS OF 1st (regulator) AND 2nd (demand valve) STAGES
for a better understanding of the following article, it is recommended to familiarize yourself with what is generally a 1st and 2nd stages, and how it works, namely: Scuba Traveller How a Scuba Diving Regulator's First Stage Works Qdivers Doha | PADI scuba diving courses and more in Qatar
There are a number of simple procedures that can be used to check the correctness of 1st, 2nd and the pressure gauge, which can be carried out without any additional equipment.
All these procedures are detailed in many sources, and they are not discussed here. As part of this instruction, it is the option that is considered when you have a pressure gauge for checking the intermediate pressure, and if you have it, you do a full cycle of checking everything you can.
There are those that are screwed directly into the LP port (Low Pressure), there are those that are connected to the expansion hose of the compensator / BSD (usually under the INTL 8 mm nozzle), which are put in the hose break 2nd (before demand valve) and are often supplemented with adjustment for the adjustment of the 2nd seat .
we connect the pressure gauge (intermediate pressure)
at the same time if you know for sure that there is some problem, and there is time to do it - then it is better to leave connected to 1st (to the 1st stage) by minimizing the hoses, and as short as possible.
at the very minimum - it's only a hose to 2nd. If the manometer in the variant for connection to the hose connection of the BSD - then the BSD hose is still needed.
it is necessary that the pressure gauge (high pressure) should remain in place.
If you check the assembled state of the "spider" (1st with 2nd assembled), without removing the excess hoses, this basically does not change anything, but it will not make it easy to identify some of the problems.
we connect the regulator (1st + 2nd + hoses + pressure gauges) to the cylinder in which at least the pressure of 100 atm ...
(this is the case if the balanced diaphragm 1st is checked, but if it is piston, then it can and will work at 100bar, give 200 can make pssst, the cause is mainly o-ring piston-scraped, scratched. Therefore it is highly desirable to check full pressure)
1) open the cylinder. slow. till the end. the HP pressure gauge quickly showed the pressure in the tank, the IP manometer abruptly jumped by an amount of about 8.5-10.5 atm and froze, and does not move further on a half-bar. - already good.
2) pressed strongly for 1 second and sharply released the button 2nd. if the manometer IP jumped down no more than 1 atm, then returned exactly to the same value (8.5-10.5) and froze in place, and the manometer HP almost did not flinch (ie notice it didn't get a chance) - all is well - the regulator is OK (within the scope of the check). (some sets of 1st-2nd can show a greater fall, it is generally not very good, but it is probably a feature of the work of a particular model, so it can not be unequivocally said that this is a critical malfunction)
(* 1) to the set pressure. As standard, the factory settings of most gear units specify an installation pressure of 9.5-10 atm. Some scuba divers can change it for themselves, or when servicing it they can be rebuilt for colder water (6.5-8.5) or for easier breathing (10.5-11, but with reconfiguration and a 2nd). There are also non-standard 1sts (for example old Soviet ones from 5 to 6.5 atm or Divex, or some type of Poseidon - 11 atm), but still the overwhelming majority of the widely used 1stes operate in the range from 9 to 10.5 atm.
now what can be faulty and how it looks:
