A ball valve with a throttle and without, what is it all about?

Hello, I haven't found a better section in the forum so ask here.
Can someone explain to me what is the difference between a ball valve in a version with a throttle and in a version without. At first, I associated it with a venturi or flange, but when I looked at the technical drawings, you can't see anything like that. However, they differ in the place where the axis of the ball passes through the body to the lever.
Could someone confirm this and explain what are the advantages of both solutions, because both variants from the same manufacturers are on sale.

Hello. Well the colleague noticed. This axle is sealed. Without a gland, the seal is not replaceable. With the gland, the seal is secured with a nut. It can be replaced or just tightened to remove the leak.

It is about the way of sealing the ball axis. A valve with a gland has a nut under the handle of the knob, theoretically used to tighten the seal. In practice, it can be different and it is not worth investing in cheap ball valves. All of them have a poor service life and what is more important is the maximum working pressure, i.e. the determination of PN and the following number.

Thank you for the answer, I was curious about the fact that there are ball valves for PLN 7 and PLN 27, while the latter were usually written with a throttle.
If those with a choke are better, why are they still produced without, for example VALVEX http://www.insbudwybrzeze.pl/view/365 the same parameters and warranty.

Hello. recently, when replacing ball valves, I found a moment and dismantled the old leaky valve (without a gland). Of course, they are dismantleable (regular right-hand threads). The leak was at the point of exit of the ball axis to the handle (i.e. under the closing handle), there are 2 o-rings that can be replaced and then surely for the valve to work. But that's not what I meant. The best thing about a leaking valve is its replacement, but sometimes there is a problem with how to remove the old one (a lot of desoldering, little space, difficult to access, etc.) and this was the case in my case, I have elegantly replaced 2 valves, and I managed to seal 4 less accessible valves without unscrewing them and without disassembling. The leak appeared under the handle, so I took the handle off, cleaned the leak (even descaled) and smeared with sealing paste, chose the appropriate o-ring, which I put on the protruding pin, a 1/2 "rubber seal and the handle and tightened it. So far, there is no droplet so it probably helped, just for how long . Of course, it is best to replace the valve and insert a new, better one, but sometimes you can easily and cheaply reseal something. Below are photos of the valve. Maybe whoever it will help.

Does it matter with which side we connect the valve in the installation, in relation to the direction of liquid flow in the installation?

Always connect the valve in the right direction (in the "valve open" position, the handle points to the rear). In some valves it may be significant, in some not. One thing is for sure important. Use valves for water for water, and valves for gas for gas. Gas valves have a yellow handle (lever), water valves - blue (cold water) or red (hot water).

Zbigniew Rusek wrote:

you should always connect the valve in the right direction (in the "valve open" position, the handle points to the rear). In some valves this may be significant, in some not. One thing is for sure important. Use valves for water for water, and valves for gas for gas. Gas valves have a yellow handle (lever), water valves - blue (cold water) or red (hot water).

For gas, you can still find valves with black handles in old installations.

These valves have a screwed body and I have encountered several times that due to stresses, especially in cold water, they broke on the twist side (cracks in the thread), so it's good to give the solid side of the valve on the side where in the event of a break it will be possible to close the damaged valve and cut off the pressure , for example, on the CO supply to the container, we put the solid side to the supply and the connected side to the container.