Если не считать распылителя, всё оборудование работает тихо.

Here если не считать is a set expression meaning if you don’t count / if we leave out / except for / apart from.

So yes, если literally means if, but in this phrase the whole chunk functions idiomatically. It does not introduce a real condition in the usual sense. The idea is:

• Если не считать распылителя...
  = If we don’t count the sprayer...
  = Except for the sprayer...

This kind of wording is fairly common in Russian, especially in slightly neutral or written-style statements.

Because after не считать in this kind of exception expression, Russian often uses the genitive.

• nominative: распылитель
• genitive: распылителя

So:

• если не считать распылителя
  = if you don’t count the sprayer / apart from the sprayer

This is a very natural pattern in Russian. Even though считать by itself often takes a direct object, in this negative idiomatic expression the genitive is common and sounds natural.

Because оборудование is grammatically singular in Russian.

It means equipment, which is a collective/mass noun. Even though it may refer to many separate pieces, Russian treats it as one whole set.

So the verb must also be singular:

• оборудование работает = the equipment is operating
• not оборудование работают

This is similar to standard English the equipment is, not the equipment are.

Because оборудование is neuter singular.

• всё = neuter singular form of all
• все = plural form of all

Compare:

• всё оборудование = all the equipment
• все приборы = all the devices

So всё agrees with the singular neuter noun оборудование.

Yes. In Russian, работать is very commonly used for machines, devices, systems, and equipment.

It can mean:

• to work
• to function
• to operate
• to run

So оборудование работает тихо means something like:

• the equipment works quietly
• the equipment operates quietly
• the equipment runs quietly

This is completely normal Russian usage.

Because тихо is an adverb, and it modifies the verb работает.

The sentence is describing how the equipment operates:

• работает тихо = works quietly / runs quietly

If you used an adjective like тихое, that would describe the noun itself:

• тихое оборудование = quiet equipment

So:

• тихо = about the manner of operating
• тихое = about the equipment as a quality

Because Если не считать распылителя is a fronted clause/expression before the main statement.

Russian punctuation regularly separates this opening part from the main clause:

• Если не считать распылителя, всё оборудование работает тихо.

So the comma marks the boundary between:

1. the exception phrase
2. the main clause

Russian generally uses commas more consistently than English in structures like this.

Yes, absolutely.

That version is very close in meaning:

• Если не считать распылителя, ...
• Не считая распылителя, ...

Both mean except for the sprayer / apart from the sprayer.

The version with если can feel a little more like if we leave X out of account, while не считая is a slightly more direct excluding X. In many contexts, the difference is very small.

The word order here is quite natural and neutral:

• Если не считать распылителя, всё оборудование работает тихо.

It presents the exception first, then the main point.

You could change the order for emphasis, for example:

• Всё оборудование работает тихо, если не считать распылителя.

This sounds more like:

• All the equipment works quietly—except for the sprayer.

So the original sentence is a straightforward, neutral way to say it, while changing the order can shift the focus slightly.