When it comes to dealing with high pressure, especially at first, many people are haunted by fear. Imagination draws a terrible picture: a burst hose high pressure with a terrible whistle it whips everything and everything, cutting through iron and people. Many will smile, but I have heard about such phobias more than once from people who are frankly afraid of PCP rifles.
Let's just say: there are phobias, but there are safety precautions. We have already written about the old ones, which are still in demand among the most economical and risky divers and airgunners. Today we are not talking about them. Let's talk about high pressure hoses.
How the HP hose works
Conventionally, a hose (in the industry it is customary to call it a high-pressure hose) consists of three parts:
Internal hose. It is sealed, made of a very elastic material, resistant to all kinds of chemical damage.
Braid. It happens in one or more layers, often made of metal mesh. Her job is to contain the pressure.
outer layer. Plastics or special rubber are often used here. The purpose of this layer is to protect the hose from cuts, punctures, deformations, etc.
It must be understood that the HP hose is a rather fragile thing that has a rather small resource. Instantaneous pressure drops during filling from 0 to 200 atmospheres wear out the hose and the inner layer is destroyed. By the way, a common misconception is that the hose can be easily damaged. It will be very difficult for you to inadvertently pierce or cut the hose from the outside. Not every knife will saw through an iron braid. The inner layer will tear by itself much earlier.
How does a high pressure hose break?
This usually happens at the place of the sleeve (on the side of the connector). The tightness of the inner layer is broken, air enters under the outer shell and begins to inflate it.
If you miss a moment and the bubble bursts, it will be very loud and scary. Actually, even in this state, the hose can be carefully used. Poke the bubble with a needle, the hose will poison, but you still have a chance to refill your rifle's reservoir.
Naturally, adhesive tape and electrical tape will not help you. If the heavy-duty outer braid is already torn, then they definitely will not hold such a strong air pressure.
The only advice I can give you about high pressure hoses is to bring a spare. You can never predict when it will burst, but the fact that this happens and can ruin the shooting is for sure.
Two were chosen for the experiment. domestic car- "Lada-112" and "Chevrolet-Niva". Both have diagonal dual-circuit brake systems. Such a scheme is the most modern, since if any circuit fails, the efficiency of the remaining circuit should theoretically be exactly half. How about in practice?
Standards for braking efficiency of the working and spare brake systems defined by GOST R 51709-2001. It contains the values stopping distance and deceleration from a speed of 40 km/h. Out of date! We will brake from 100 km/h – this threshold has been used all over the world for a long time, evaluating the effectiveness of brakes on dry pavement.
We start with the "twelfth" - this car is easier, and closer to the ground - it's not so scary to jump into the arms of an experiment. Determine the stopping distance working system. We brake on the verge of a skid, achieving maximum deceleration, that is, the driver imitates ABS, trying to prevent the wheels from locking.
A few repetitions - and you manage to catch the right effort on the pedal. It has to be smoothly pressed - the front brakes heat up and their effectiveness drops. At the same time, the braking distance from 100 km / h is 43.9 m.
Having disconnected the rear tube from the master cylinder, we “half” the brakes: now the car will brake only with two wheels - the front left and the rear right. We repeat the exercise.
The pedal travel has approximately doubled, but at the same time it has not fallen to the floor, contrary to the stories of experienced ones. The car strives to jump to the left - in the direction of the braking front wheel, and in order to keep it within the lane, you have to turn the steering wheel to the right by about 40-50 degrees. But even then "Lada" scours the strip.
For three attempts, the spread of the braking distance is from 93.1 to 112.1 m. average value- 103.5 m, that is, the stopping distance has increased by 2.36 times! The reason is that part of the traction force, which works only for deceleration with serviceable brakes, when braking in one circuit is spent on maintaining the course, that is, on combating drift. This part, as we see, is quite significant.
We repeat the measurements with another contour. First, we put the tube in place, pump the system and make sure that there is no air in it - the braking distance does not exceed 44 m. Then we disconnect the tube of another circuit.
At emergency braking the effect is similar - pulling towards the front wheel with a working brake, in our case to the right. The braking distance increased to 101.2–110.8 m. The average value is 105.1 m, that is, an increase of 2.39 times.
The difference in the efficiency of the circuits is only 1.5%, the average stopping distance is 104.3 m, the average deceleration is 3.68 m/s2.
Let's check how the car behaves if its course is not corrected by the steering wheel during braking. Another approach - the steering wheel is only "straight". But when the car leaves for the next lane, you have to turn the steering wheel to keep from changing lanes. If the steering wheel is not operated at all, the car will change at least two lanes before coming to a complete stop!
We had a professional test driver behind the wheel, often working in extreme conditions. In addition, we performed braking on dry pavement with a high coefficient of adhesion. Most likely, on a wet or icy road, it will be impossible to keep the car on course. In everyday language, this means a skid and a turn, which can end very sadly.
It is the turn of the Chevrolet Niva. In normal mode, when braking from a hundred, the braking distance averaged 53.3 m. But our task is not to compare the cars with each other, but to evaluate the difference in brake efficiency. How many meters will we slow down with one circuit?
Several races - and the answer is ready: on average - 121.6 m. But the increase in the path is less than on the "twelfth" - only 2.28 times. But the sensations are less pleasant, and it's not about big move brake pedal - it increased approximately the same as on the "Lada" - but in the behavior of the car.
When braking on the verge of skidding, the car pulls towards the working front brake, like on the Lada, only weaker. The corrective action by the steering wheel to stay in your lane is less - the steering wheel needs to be turned 30-40 degrees. In non-lock braking, as the brakes heat up, the required pedal force increases perceptibly. But if the wheel is blocked, which is quite difficult to resist, an unpleasant surprise awaits the driver - the Chevy Niva rushes in the opposite direction, where it is pulled by the front wheel turned to keep the course with the circuit turned off.
To summarize: if one of the circuits fails, the braking distance increases by almost two and a half times. At the same time, both cars noticeably scour the road and strive to jump to the neighboring lane, and if you do not react in time, then further. The behavior of each machine has its own nuances. The Lada pulls harder than the Chevy Niva. But the all-terrain vehicle, when the front wheel is blocked, changes the direction of “steer”.
OUR RECOMMENDATIONS
With a sudden sharp increase in brake pedal travel, do not panic, continue to press on it until the remaining good circuit is activated. Be prepared to turn the steering wheel the right side to keep the car in its lane.
1. Turn off the water, turn off the electricity - note - just disconnecting the washer from the power source - it may not be enough, sometimes electrical cables are laid along the walls under the floor, in which case they can get wet, which creates a risk of a short circuit.
2. Collect water from the floor as quickly as possible before it goes down.
3. Go down to the neighbors on the floor below, ask if everything is in order with them. If not, then follow the instructions from the article:.
The service life of the hose depends both on the correct connection and on the constancy of the water pressure.
1. Correct connection washing, dishwashers to the water supply system. Either official service center, or a plumber from the Housing Office. Be sure to keep your receipts. Please note that the machine must have a separate tap that shuts off the water supply to it. When the machine does not wash, it is recommended to turn off the water.
2. Use of quality materials. Alas, the flexible hoses that can be found in the neighboring utility room cannot cope with pressure surges in our apartments. Keep your receipts. Use special ones - they are more expensive than ordinary ones, but much more reliable.
3. The presence of water pressure regulators in the apartment and.
4. Special blocking devices that shut off the water in case of leaks. are put directly together with a hose to cold water.
Washing machine leaked
From a reader's story.
With the advent washing machines-machines flooding cases began to increase. The situation was similar with our apartment.
Somehow, a neighbor from above forgot to throw a hose into the bathroom, from which water flows from the washing machine. And she left the house, leaving the laundry on. First, water began to appear on my ceiling in the bathroom, then in the toilet, in the hallway, in the kitchen.
There are many reasons why washing machines leak. The main thing here is to react quickly, turn off the machine and eliminate puddles, so you can avoid flooding your neighbors.
At first the ceiling became wet, and then completely warm water began to drip on our heads. Funny or not, but my child ran around the apartment under an umbrella, for him it was some kind of entertainment. Thank God that this neighbor often went on business trips and left the keys to the apartment with the neighbors. They then helped open the door and eliminate the flood.
Fortunately, the furniture in our apartment was not damaged, but terrible orange stains remained on the ceiling. Fortunately, the neighbor was a conscientious woman and reimbursed the cost of painting the ceiling, but we had to deal with this matter ourselves, since she did not pay for the services of the workers.
By the way, these yellow spots reappeared after a few months, it is simply useless to fight them.
If it bursts brake hose, only half of the brakes fail. How the car behaves in this case was checked by Sergey Mishin and Valery Pavlov.
For the experiment, we chose two domestic cars - "Lada-112" and "Chevrolet-Niva". Both have diagonal dual-circuit brake systems. Such a scheme is the most modern, since if any circuit fails, the efficiency of the remaining circuit should theoretically be exactly half. How about in practice?
The standards for braking efficiency of the working and spare brake systems are determined by GOST R 51709-2001. It shows the braking distance and deceleration from 40 km/h. Out of date! We will brake from 100 km/h – this threshold has been used all over the world for a long time, evaluating the effectiveness of brakes on dry pavement.
We start with the "twelfth" - this car is easier, and closer to the ground - it's not so scary to jump into the arms of a mysterious experiment. We determine the braking distance with a working system. We brake on the verge of a skid, achieving maximum deceleration, that is, the driver imitates ABS, trying to prevent the wheels from locking.
A few repetitions - and you manage to catch the right effort on the pedal. It has to be smoothly pressed - the front brakes heat up and their effectiveness drops. At the same time, the braking distance from 100 km / h is 43.9 m.
Having disconnected the rear tube from the master cylinder, we “half” the brakes: now the car will brake only with two wheels - the front left and the rear right. We repeat the exercise.
The pedal travel has approximately doubled, but at the same time it has not fallen to the floor, contrary to the stories of experienced ones. The car strives to jump to the left - in the direction of the braking front wheel, and in order to keep it within the lane, you have to turn the steering wheel to the right by about 40-50 degrees. But even then "Lada" scours the strip.
For three attempts, the spread of the braking distance was from 93.1 to 112.1 m. The average value was 103.5 m, that is, the braking distance increased by 2.36 times! The reason is that part of the traction force, which works only for deceleration with serviceable brakes, when braking in one circuit is spent on maintaining the course, that is, on combating drift. This part, as we see, is quite significant.
We repeat the measurements with another contour. First, we put the tube in place, pump the system and make sure that there is no air in it - the braking distance does not exceed 44 m. Then we disconnect the tube of another circuit.
In case of emergency braking, the effect is similar - pulling towards the front wheel with a working brake, in our case to the right. The braking distance increased to 101.2–110.8 m. The average value is 105.1 m, that is, an increase of 2.39 times.
The difference in the efficiency of the circuits is only 1.5%, the average stopping distance is 104.3 m, the average deceleration is 3.68 m/s2.
Let's check how the car behaves if its course is not corrected by the steering wheel during braking. Another approach - the steering wheel is only "straight". But when the car leaves for the next lane, you have to turn the steering wheel to keep from changing lanes. If the steering wheel is not operated at all, the car will change at least two lanes before coming to a complete stop!
We had a professional test driver behind the wheel, often working in extreme conditions. In addition, we performed braking on dry pavement with a high coefficient of adhesion. Most likely, on a wet or icy road, it will be impossible to keep the car on course. In everyday language, this means a skid and a turn, which can end very sadly.
It is the turn of the Chevrolet Niva. In normal mode, when braking from a hundred, the braking distance averaged 53.3 m. But our task is not to compare the cars with each other, but to evaluate the difference in brake efficiency. How many meters will we slow down with one circuit?
Several races - and the answer is ready: on average - 121.6 m. But the increase in the path is less than on the "twelfth" - only 2.28 times. But the sensations are less pleasant, and the point is not in the large stroke of the brake pedal - it has increased approximately the same as on the Lada - but in the behavior of the car.
When braking on the verge of a skid, the car pulls in the direction of the working front brake, just like on the Lada, only weaker. The corrective action by the steering wheel to stay in your lane is less - the steering wheel needs to be turned 30-40 degrees. In non-lock braking, as the brakes heat up, the required pedal force increases perceptibly. But if the wheel is blocked, which is quite difficult to resist, an unpleasant surprise awaits the driver - the Chevy Niva rushes in the opposite direction, where it is pulled by the front wheel turned to keep the course with the circuit turned off.
To summarize: if one of the circuits fails, the braking distance increases by almost two and a half times. At the same time, both cars noticeably scour the road and strive to jump to the neighboring lane, and if you do not react in time, then further. The behavior of each machine has its own nuances. The Lada pulls harder than the Chevy Niva. But the all-terrain vehicle, when the front wheel is blocked, changes the direction of “steer”.
OUR RECOMMENDATIONS
With a sudden sharp increase in brake pedal travel, do not panic, continue to press on it until the remaining good circuit is activated. Be prepared to turn the steering wheel in the right direction to keep the car in your lane.
Press the pedal carefully, trying to accurately dose the applied force. Blocking the front wheel will increase the braking distance, and sometimes change the direction of the slip.
When blocking the front wheel (accompanied by a specific whistling sound), slightly loosen the pressure on the pedal, but do not release it completely.
Do not try to pump the brake pedal by releasing it completely, even for a short time - such actions will lead to unnecessary consumption brake fluid through a faulty circuit, and the lost time will only increase stopping way.
At emergency braking try to go around the obstacle if the adjacent lanes are free, but remember that a collision in the adjacent lane Rules traffic interpreted not in your favor.
