La válvula está cerrada.

Because válvula is a feminine noun in Spanish, so it takes the feminine singular article la.

• la válvula = the valve
• una válvula = a valve

As in most cases, the gender is a grammatical feature of the noun, so the article and any matching adjective must agree with it.

Because cerrada agrees with válvula, which is feminine singular.

The base form is the past participle of cerrar (to close):

• cerrado = masculine singular
• cerrada = feminine singular
• cerrados = masculine plural
• cerradas = feminine plural

So:

• La válvula está cerrada.
• El grifo está cerrado.
• Las válvulas están cerradas.

Spanish uses estar here because closed is being treated as a state or condition, not as an essential characteristic.

• estar cerrado/a = to be closed
• ser is generally not used here for the normal idea that something is in a closed state

So La válvula está cerrada means the valve is currently in the state of being closed.

This is one of the very common uses of estar:
estar + past participle/adjective to describe a resulting condition.

It is originally a past participle of the verb cerrar, but in this sentence it is functioning like an adjective after estar.

So grammatically, you can think of it as:

• coming from the verb cerrar
• but describing the valve’s current state

That is why it agrees in gender and number with the noun:

• La puerta está cerrada.
• El libro está cerrado.

Not exactly in the usual sense.

La válvula está cerrada describes a state: the valve is in a closed condition. It does not focus on who closed it.

A more explicit passive would be something like:

• La válvula fue cerrada por el técnico. = The valve was closed by the technician.

So:

• está cerrada = state/result
• fue cerrada / ha sido cerrada = passive event/action

Learners often confuse these, so it is a very common question.

The normal order is:

• La válvula = subject
• está = verb
• cerrada = complement/adjective

So the structure is:

subject + estar + adjective/past participle

This is the most neutral and natural order.

Yes, you can, but it sounds more marked or context-dependent.

La válvula está cerrada is the neutral statement.

Está cerrada la válvula may be used for emphasis, contrast, or in contexts where the speaker is focusing first on the state:

• Sí, está cerrada la válvula.

For a learner, the safest default is La válvula está cerrada.

Válvula is pronounced roughly like VAL-vu-la, with the stress on the first syllable.

The written accent in á shows where the stress goes:

• VÁL-vu-la

Without the accent mark, Spanish spelling rules would suggest a different stress pattern, so the accent is important.

A rough pronunciation guide for the whole sentence is:

la VAL-vu-la es-TA ce-RRA-da

In Spain, z in many regions is pronounced like the th in think, so válvula keeps a normal v/b sound, while there is no z here to worry about.

Here cerrada means closed or shut.

With something like a valve, it usually means it is not allowing flow because it is in the closed position.

The exact English wording may vary slightly by context:

• closed
• shut
• shut off sometimes in technical contexts

But in Spanish, estar cerrada is the standard way to express that state.

Yes. Válvula is a general word for valve and can be used in mechanical, industrial, medical, and other technical contexts.

For example, it could refer to:

• a pipe valve
• an engine valve
• a heart valve

The sentence itself does not specify which kind; the context tells you.

You make all the agreeing parts plural:

• Las válvulas están cerradas. = The valves are closed.

Changes:

• la → las
• válvula → válvulas
• está → están
• cerrada → cerradas

This is a good example of how article, verb, and adjective all work together.

You place no before the verb:

• La válvula no está cerrada.

That is the standard Spanish word order for negation:

subject + no + verb + complement

You can simply use the same words with question intonation, and in writing add question marks:

• ¿La válvula está cerrada? = Is the valve closed?

You may also see inverted order, especially in more formal or written styles:

• ¿Está cerrada la válvula?

Both are correct. For learners, the first version is often easiest to recognize because it keeps the same order as the statement.

Because cerrada is not a noun here; it is describing the state of la válvula.

Spanish does not normally use an article before an adjective in this kind of structure:

• La puerta está abierta.
• La tienda está cerrada.
• La válvula está cerrada.

So cerrada works as the descriptive part of the sentence, not as a separate noun phrase.