{"id":53536,"date":"2019-12-04T00:00:00","date_gmt":"2019-12-03T21:00:00","guid":{"rendered":"https:\/\/prohoster.info\/blog\/blog_prohoster\/pravda-o-zheleznodorozhnyh-tormozah-chast-3-pribory-upravleniya"},"modified":"2020-02-18T14:01:26","modified_gmt":"2020-02-18T11:01:26","slug":"pravda-o-zheleznodorozhnyh-tormozah-chast-3-pribory-upravleniya","status":"publish","type":"post","link":"https:\/\/prohoster.info\/en\/blog\/news\/pravda-o-zheleznodorozhnyh-tormozah-chast-3-pribory-upravleniya","title":{"rendered":"The Truth About Railroad Brakes: Part 3 \u2014 Control Devices","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

It's time to talk about devices designed for brake control. These devices are called 'valves', although a long evolutionary path has taken them quite far from what we typically understand as valves, transforming them into quite complex pneumatic automation devices.<\/p>\n

The good old spool valve 394 is still in use on rolling stock.<\/i>
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1. Engineer's Valves \u2014 A Brief Introduction<\/h1>\n

\nBy definition<\/p>\n

The train engineer's valve is a device (or a set of devices) designed to control the magnitude and rate of pressure change in the train's brake line.<\/p><\/blockquote>\n

Current train engineer's valves can be divided into direct control devices and remotely controlled valves.<\/p>\n

Direct control devices are the classics, installed on the vast majority of locomotives, multiple units, and also on specialized rolling stock (various road machines, railcars, etc.) are the engineer's valves No. 394 and No. 395. The first one, shown in the KDPV, is installed on freight locomotives, while the second is used on passenger trains.<\/p>\n

In pneumatic terms, these valves do not differ from each other at all. They are absolutely identical. The 395 valve has, cast as part of its upper section, a projection with two threaded holes where the 'bank' of the electro-pneumatic brake control is installed.<\/p>\n

The 395 engineer's valve in its natural habitat.<\/i>
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\nThese devices are often painted bright red, indicating their exceptional importance and the special attention that both the locomotive crew and the technological personnel servicing the locomotive should pay to them. Another reminder that the brakes on the train are everything.<\/p>\n

The feed line (PM) and brake line (TM) pipes are directly connected to these devices, and by turning the handle, direct control of the airflow is achieved.<\/p>\n

In remote-controlled cranes, the so-called control controller is not the crane itself; instead, it transmits commands to a separate electro-pneumatic panel, which is installed in the locomotive's machine room via a digital interface. The domestic rolling stock uses the much-criticized crane for the driver of class No. 130, which has been trying to establish itself in the rolling stock for quite some time.<\/p>\n

The controller for crane No. 130 on the cab of the EP20 electric locomotive (on the right, next to the manometer panel)<\/i>
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\nPneumatic panel in the machine room of the EP20 electric locomotive<\/i>
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\nWhy was it designed this way? To provide a standard way to manage automatic brakes in addition to manual control, for example, from the train control system. On locomotives equipped with the 394\/395 crane, a special attachment was required on the crane for this purpose. The idea was that the 130 crane would be integrated into the train control system via the CAN bus, which is used in domestic rolling stock.<\/p>\n

Why did I call this device much-criticized? Because I witnessed its first appearance on rolling stock. Such devices were installed on the first models of new Russian electric locomotives: 2ES5K-001 \"Yermak\", 2ES4K-001 \"Donchak\", and EP2K-001.<\/p>\n

In 2007, I participated in the certification tests of the 2ES4K-001 electric locomotive. On this machine, the 130 crane was specifically installed. However, even then, there were talks about its low reliability; moreover, this technological marvel could spontaneously release the brakes. Therefore, it was soon abandoned, and the \"Yermaks\", \"Donchaks\", and EP2Ks went into production with 394 and 395 cranes. Progress was postponed until a new device was developed. This crane returned to the Novocherkassk locomotives only when the EP20 electric locomotive began production in 2011. By the way, the EP2K-001 with the 130 crane is currently decaying at the storage base, as I recently learned from a video by a railway enthusiast.<\/p>\n

However, the railway workers do not fully trust such a system; hence, all locomotives equipped with the crane No. 130 are also fitted with backup control cranes, which allow for simplified direct control of the pressure in the brake pipeline.<\/p>\n

Backup brake control valve in the driver's cabin of EP20<\/i>
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\nLocomotives also have a second control device installed \u2014 auxiliary brake valve<\/i> (KVT), designed to control the locomotive brakes independently of the train brakes. Here it is, to the left of the train valve<\/p>\n

Auxiliary brake valve, model No. 254<\/i>
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\nThe photo shows a classic auxiliary brake valve, model No. 254. It is still widely installed on both passenger and freight locomotives. Unlike the wagon brakes, the brake cylinders on the locomotive never<\/b> are not directly filled from the storage reservoir. Although both the storage reservoir and the air distributor are installed on the locomotive. In general, the braking system of the locomotive is more complex because there are more brake cylinders on the locomotive. Their total volume significantly exceeds 8 liters, so it will not be possible to fill them from the storage reservoir to a pressure of 0.4 MPa \u2014 it is necessary to increase the volume of the storage reservoir, which will increase its charging time compared to the wagon's SR.<\/p>\n

On the locomotive, the cylinders are filled from the main reservoir, either through the auxiliary brake valve or through a pressure relay that is acted upon by the air distributor activated by the driver's train valve.<\/p>\n

Valve 254 has the particular feature that it can also operate as a pressure relay, allowing for the release (stepwise!) of the locomotive brakes when the train is halted. This system is called the KVT switching scheme as a repeater and is used on freight locomotives.<\/p>\n

The auxiliary brake valve is used during shunting movements of the locomotive, as well as for securing the train after stopping and during standing. Immediately after the train stops, this valve is set to the final braking position, and the train's brakes are released. The locomotive's brakes can hold both the locomotive and the train on quite a significant incline.<\/p>\n

Modern electric locomotives, such as the EP20, are equipped with different KVT models, for example, model No. 224<\/p>\n

Auxiliary brake valve model No. 224 (on the right side of a separate panel)<\/i>
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2. Structure and principle of operation of the driver's valve model No. 394\/395<\/h1>\n

\nSo, our hero is the old, tried-and-true crane 394 (and 395, but it's similar, so I will refer to one device while meaning the other). Why this one and not the modern 130? First, the 394 crane is more common today. Second, the 130 crane, or rather its pneumatic panel, functions similarly to the old-timer 394.<\/p>\n

Driver's crane, model No. 394: 1 \u2014 outlet valve base; 2 \u2014 lower housing; 3 \u2014 sealing sleeve; 4 \u2014 spring; 5 \u2014 outlet valve; 6 \u2014 sleeve with outlet valve seat; 7 \u2014 balancing piston; 8 \u2014 rubber sealing sleeve; 9 \u2014 brass sealing ring; 10 \u2014 middle housing; 11 \u2014 upper housing; 12 \u2014 spool; 13 \u2014 control handle; 14 \u2014 handle lock; 15 \u2014 nut; 16 \u2014 clamping screw; 17 \u2014 rod; 18 \u2014 spool spring; 19 \u2014 clamping washer; 20 \u2014 mounting studs; 21 \u2014 locking pin; 22 \u2014 filter; 23 \u2014 supply valve spring; 24 \u2014 supply valve; 25 \u2014 sleeve with supply valve seat; 26 \u2014 diaphragm of the reducer; 30 \u2014 adjusting spring of the reducer; 31 \u2014 adjusting cup of the reducer.<\/i>
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\nWhat do you think? A serious device. This device consists of an upper (spool) part, a middle (intermediate) part, a lower (balancing) part, a stabilizer, and a reducer. The reducer is shown at the bottom right of the figure; I will show the stabilizer separately.<\/p>\n

Stabilizer for driver's crane model No. 394: 1 \u2014 plug; 2 \u2014 throttle valve spring; 3 \u2014 throttle valve; 4 \u2014 throttle valve seat; 5 \u2014 calibrated hole with a diameter of 0.45 mm; 6 \u2014 diaphragm; 7 \u2014 stabilizer housing; 8 \u2014 stop; 10 \u2014 adjusting spring; 11 \u2014 adjusting cup.<\/i>
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The crane's operating mode is set by turning the handle, which rotates the spool tightly fitted (and thoroughly lubricated!) to the mirror in the middle part of the crane. There are seven positions, traditionally denoted by Roman numerals.<\/p>\n