Well... yes, but most of the smaller ones will not handle the thicker latex formulations. They work fairly well on stains and thinner applications. A true airless sprayer used by professionals does a great job, but here in the U.S., such a model will cost $500 up to $3,000. I use one to paint my house and barns and they are great with any paint. I rent rather than buy...
The sprayers are OK, but what you need to realise is that the majority of them are marketed with water based solutions which have a very limited lifespan on the wood with questionable protection properties. My recomm. is that you look to use a spirit based protector such as Cuprinol / Ronseal etc. These soak into the wood much quicker and deeper and last longer. Of course the downside is that they will be dearer. You pay for what you get IMO.