Does anyone know these flanges?

Is there someone familiar with this type of flanges as seen in the photoalbum below? In detail they are somewhat different then the usual welding neck flanges (take a good look at the bolts).
I'm looking for some information about type, code, supplier etc etc.

Photoalbum

Thanks in advance

Edwin

edwin16 ...I've got a question for you, are all these types of flanges only located on the "equipment" or vendor piping? ...OR does all the associated piping from this equipment through out the facility have these types of flanges?

They are located on the valve blocks, in the pipeline and on the cilinders. It's a (250 Bar) hydraulic system of a press located in Belgium, possibly delivered by a (American) vendor. The customer does not have any information of it.

Edwin

"On block valves"!?? ...Do you have a picture of this application? ...The reason I'm asking is because I don't believe they are a "standard" type of flange. I believe that some vendor somewhere took standard flanges and did additional machining to use socket head cap screws with female threaded companion flange mated to it (and was why I was asking if they were only used on vendor piping and not thru out the facility)! …NOW it's just a guess on my part, to be honest I've never encountered these "types" of flanges before either, AND I'm not sure why a vendor would do something like this (other then ease of assembly), but I'd guess it would be a lot better/easier to replace these flanges (where possible) with a "normal" type of flange & save everybody a lot of headaches! ..Good Luck!

"On block valves"!??

Not on block valves...I never mentioned block valves.
They pipelines are connected to valve blocks. I mean (connection-) blocks where valves/servos etc are mounted to. It is partly visible on one of the photos.
This is very common in the hydraulic industry.

I've never encountered these "types" of flanges before

Neither have I.
Normally we use 3000/6000 psi square or SAE flanges (AVIT and/or STAUFF make) in the hydraulic industry but I've never seen these before.

...with a "normal" type of flange

Define "normal". You mean "normal" DIN or ASME flanges? That's very uncommon in the hydraulic industry.

edwin16 ..."They are located on the valve blocks"

Sorry I took this to mean block valves. ...What I mean by "normal" is any standard type flange in any code ...BUT one that has not been modified beyond the factory fabrication. As I indicated I believe the ones you are asking about here are "vendor" modified per their application needs. It may be nice for the vendor, but in today's real world, that type of "stuff" just cause problems and cost extra money.