Ball valves against gate valves and globe valves in the refinery

[Rustam1]

Hello everybody!

I have questions.

We have produced ball valves with gate hard alloy (cermet) TiC- (Ni-alloy). This is not a coating - valves are completely made of wear resistant cermet. The specific weight (6,5 g / cm3) and the cost of manufacturing the cermet is 2.5 times lower than that of WC-Co cemented carbide. Ball valves have been successfully tested for > 3.5 years at the refinery.
We want to promote this project.
The advantages of ball valves compared with gate valves and globe valves:
-reliability and long service life;
-minimum hydraulic resistance;
-small weight and dimensions;
-high speed "closing-opening."

Questions:
-is an obvious whether these advantages of ball valves;
-what percentage of the use of ball valves, gate valves and check valves in refineries;
-what dynamics - the proportion of ball valves increases or it remains constant;

I am very grateful if you to express their views, or give references to any sources with numeric data.

Your answers will help to adjust our plans for the future, which are associated with the investment.

Thank you!

 

[MJCronin]

What is the size range offered of these valves ?

MJCronin
Sr. Process Engineer

 

[Rustam1]

Dear MJCronin,

We are at the stage of experimental work and produced ball valves DN50mm, PN25-40mm. Working temperature 550-600 °C - limited due to the properties of the materials of springs and seal rings.
Operating temperature cermets - up to 1100 °C.
The plans - manufacture of ball valves with up to DN200mm.

Thank you

 

[MickMc]

In my view as piping engineer the choice of ball vs gate for manual block valves is client driven due to preferences and/or experience and economics. My last 2 projects had mainly ball or butterfly whilst current has mainly gate and this is because the client normally uses gate which I believe is the cheapest option although I would suspect their Ops would prefer ball for ease of use.

 

[Danlap]

Hi Rustam1,

It really depending on your service, whether dirty / fouling or not. And also the tightness requirement of the valves itself. Among other parameter as well of course.
If this is for existing refinery (Brownfield) with good experience using Ball valve; used for Probe insertion; requires fast movement; etc. than Ball valve might be suitable.
IMHO, seeing your requirement of service condition, shall Ball valve to be an option, than it would be Metal to Metal with more or less special packing / extended Bonnet / Heat dissipation Bonnet in order to protect the sealing component to environment. As conservative Valve Engineer, I tend to generalize Graphite will oxidized after exposed to temperature 450 deg Celcius or above.

Personally if there is no specific requirement I would select Gate valve, Triple offset Butterfly valve and or Globe valve. Why not Ball:
a. The Ball and Seat in fouling medium is prone to scratch
b. There are a few supplier who can do this special Ball valve, and in the future you will be depending on their deliver-ability.
c. Ball valves consist of many small spare parts e.g. Springs for the Seats, Tight Shut Off (TSO) Ball valve requires really tight tolerance, Om which shall introduced to high temperature may prone to non-homogeneous thermal expansion. It might be stuck when you requires to Operate it.
d. In services with risk of flashing and or cavitation, the engineering of Ball valve requires more special attention. One may end up selecting Rising Stem Ball valve.
e. others.

of course other valves have other disadvantage and advantage as well.
Suggest to make a matrix per service and which paramater would be the highest priority (tightness, speed of Operation, throttling capability, price, etc.). Then you will have a better feeling of selection


Regards,
MR

All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected

 

[Rustam1]

Hi, Danlap

Many thanks for the detailed answer.
Previously I would like to clarify:
1. Cermet TiC-Me we have developed a long time ago for use in punching tools. After this we decided to use a cermet in the ball valve.
2. Our technology is most effective in hard and wear-resistant products cermet complex configuration. That product is the ball of the ball valve.

Operating temperature of 600 C in graphite - is probably the desire of sealing materials manufacturers.
That's right - the real operating temperature on the basis of the characteristics of graphite, even after treatment with different compositions can not exceed 450-500 C.

a. In the high-quality ball valves seat remove the solids with surface of the ball.
b. Yes there are large suppliers of ball valves for severe conditions. However, we will move in the selected direction, including and interact with them.
с. Cermet TiC-Me efficiently processed by grinding with diamond tools. We worked out the technology of grinding with ensure good contact seat with the ball. To eliminate the occurrence of backlash the ball and seat must be made of the identical material and have the same thermal expansion. There are nickel alloys for springs - long life and not flow at temperatures up to 550 C.
d. We produce ball valves as a shut-off valve. After this also for regulation.

Он the lines of coke in refinery between the wedge and seat fall solids. Shutter wear and tightness is lost. Deteriorating quality of the product. There is a fire hazard, explosion hazard, soil pollution.
Every 6 months is remove the valve, grinding wedge and seat.
High-quality ball valves (ball and seat are covered with tungsten carbide, chromium carbide with cobalt and nickel) are very expensive - more than 10 times more expensive than similar gate valves. Despite this, even in Russia at a very important lines began to replace the gate valve on high-quality ball valves. This is rare.

Therefore I decided to find out the state of in US and the world - what is the share of ball valves in the total shut-off valves in the toughest conditions. It is growing or not?

Thanks to all

 

[Danlap]

Hi Rustam1,

To be honest, I have no experience with Cermet that I am aware of.

Hard facing (HF) / material selection of course have advantage and disadvantage. Some of the disadvantages that are already agreed/experienced is incorporated in Best Practices, and some still remains not yet justified in global engineering discussion. Again, some conservative metallurgist and engineers tend to avoid this disadvantages whether it is already formally addressed or not. Most of these engineers are stationed in live Plants where wrong selection is never allowed.
Some of the HF limitiation (shall exposed to the wrong process conditions) are:
- Some Stellite (Cobalt based) family are prone to be attacked by Amine services, and also some Stellite considered as the softest HF among all
- Chromium family prone for SCC for High temperature / high pressure Hydrogen service
- TC which is brittle, is not preferable for unavoidable vibrated line (prone for Peak Stress(es))
- etc.
Not sure what is the limitation of Cermet TiC-Me??

Severe service Ball valve is basically survival of the fittest industry.
Shall during engineering process, Ball valve selected for some reason (speed, minimum pressure drop in Fully open position, etc.), then most likely the End user will prefer the already well known and proven manufacturer. To name a few: MOGAS, Flowserve, ValvTechnologies, etc.
Indeed this is niche market, but for sure there is a growing demand.

Good luck,
Regards,
MR

All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected

 

[moltenmetal]

It's hardly a niche market any more- every Tom, Dick and Harry who makes a soft-seated ball valve is trying to migrate up-market. At last check I think there were about 20 people flogging metal seated ball valves to us of one description or another, though some of them have subsequently been eaten by a megacorp like Flowserve or Cameron.

 

[Rustam1]

The difficulties are clear, but we are spent quite a lot of effort and money and we have much progress on the development of ball valves from cermet TiC-Me - I wrote on the positive results of production tests .
Therefore, the transition to other areas we not can to consider.
Thank you all for helpful criticisms and recommendations. They really helped to realistically assess our development and adjust work plans.
Perhaps there will be new criticisms, recommendations and ideas.

Thanks you all.