Who claims that valve maintenance doesn´t pay of
Most of you readers who have read my articles knows that I´m a great fan of valve maintenance, cleaning, lubricating and moving the valves on a regular basis. This will prolong their performance and lifetime. However, there are some arguing that it´s too expensive; as one needs personnel and time to be able to […]
Valves in Severe service
This issue of Valve World magazine are related to severe service, and that put a question in my head: What is severe service? If that question were asked, I think most would probably answer: Sour service, sandy service, high velocity or cryogenic, to mention some. And yes that is examples of severe service, but could […]
The how (and why) of maintenance part 12
Pre-evaluating before maintenance When performing maintenance on a leaky ball valve, there is a lot of information that must be evaluated before the actual maintenance is carried out. One must evaluate the media: Is it a clean gas, or is it heavy hydrocarbons with a lot of pollution? Is there an aggressive or sour […]
The how (and why) of maintenance part 11
The use of the auxiliary valve in ball/gate valves As discussed in previous articles there is some important equipment witch is needed to be able to perform maintenance on valves. Without the lubrication fittings it is not possible to inject valve cleaner, lubricants or sealing component. When injecting into pressurized valves, leak lock must […]
The how (and why) of maintenance part 10
The injection of lubricants After installing the leak lock on to your fitting, it´s time to inject cleaner, lubricant or sealing component. To be able to inject anything into the valve you need a pump. It may be a pneumatic or a manual pump, it does not matter what type of pump you are […]
The how (and why) of maintenance part 9
The lubrication fittings In this series of articles, we have been discussing the need for lubrication fitting and why one should use valve cleaner and sealing component. We have also been looking at why one should have an auxiliary valve in the cavity of the main valve. We all know that all […]
The how (and why) of maintenance part 8
The lubrication fittings To be able to perform maintenance on valves; inject valve cleaner, lubrication or sealing component there is a need for injection points that connects the lubrication canals in the body and to the seat; as illustrated in figure 42. On a trunnion ball valve there should be an inner check valve […]
The how (and why) of maintenance part 7
The use of sealing component as a barrier As one can understand, the lubrication fittings to the stem are an important part when it comes to prolonging the life span of a valve. As discussed in previous articles it is possible to save millions by millions when prolonging the life of a leaky valve. […]
The how (and why) of maintenance part 6
The case with the six valves in the previous article is only on of many examples where the lack of proper maintenance / preservation of the valves was the reason behind the problems. There are many different agendas when it comes to building a plant and one is to get the investment cost as low […]
The how (and why) of maintenance part 5
As explained in the previous articles in this series it is important to understand what can happen and why things do happens. In the last 40 years I have been working with valves, I have learned that the normal way of solving a valve problem is to by a new valve to replace the troublemaker. […]
The how (and why) of maintenance part 4
As one can understand, valve maintenance in not as easy as many tend to believes, it is not as claimed by some; just inject some diesel or kerosene, if that does not work replace the valve with a new valve. In the last 3 years I have performed valve maintenance on quite a lot of […]
The how (and why) of maintenance part 3
To be able to maintain a trunnion ball valve one must have access to the interior of the valve. For that reason the valve should be equipped with lubrication fittings and auxiliary valve/s. As discussed in part one and two in this series the number of injection points and internal seat canals needed, must be […]
Why and how to maintain trunnion ball valves part 2
In the first article we discussed the spindle seal and whiter or not there spindle was equipped with a lubrication fitting making it possible to lubricate or seal the valve in case of a external leakage out past the stem seal. The next item on the list was lubrication fittings and connecting canals to the […]
Why and how to maintain trunnion ball valves part 1
I will start with a question: Have you heard about maintenance free trunnion mounted ball valves? – – Yes. So have I, many times. Several times I have heard the statement: The valve is lubricated for life. Perfect, then you will save the time maintaining the valve. But don´t forget, the life of that valve can […]
Maintenance on the Christmas trees part 2
As discussed in part 1 it is important with fittings in the right positions if they are to fit the purpose of injecting and draining from the valve internals. Start at the bottom in figure 6: Valve 1: The manual master valve. This is the most important valve as it is the one closest to […]
Maintenance on the Christmas trees part 1
As the year 2015 is closing up an we are getting close to Christmas it is in this world of valves natural to think of Christmas trees, not the ones in the living room made of wood or plastic, but the X-mas trees on the well head or on the sea-bed securing us the flow […]
Double block & bleed: understanding a barrier – part 6
As illustrated in this series of articles, there are many ways of creating double block & bleed or double isolation and bleed. But in this name you need to ha a depressurized volume between the two barriers and the name itself makes a problem. If taking a double piston ball valve like the one illustrated […]
Double block & bleed: understanding a barrier – part 5
When preparing for å job to be done most production personnel in the hydrocarbon industry are focused upon the double block & bleed. For a job to be safely done everything has to be in accordant with the company policy, witch normal are double block & bleed up to the point where the job are […]
Double block & bleed: understanding a barrier – part 4
In the last three articles we have been looking at different ways for valves to seal, different valve constructions like double expanding gate, solid slab gate, trunnion mounted ball valves with self-relief seats, double piston seats or the combination DPE / SPE construction. I would like to go back to the beginning of the first article […]
Double block & bleed: understanding a barrier – part 3
If looking at a double piston seat arrangement like the one illustrated in Figure 10, you can see that with a system- pressure from the left hand side of the valve the red marked area on the back of the seat will represent the seal-force area of the upstream seat. When decreasing the downstream pressure […]
Double block & bleed: understanding a barrier, part two
Let us start this part with a question: What makes a valve seal? And the answer is: Force from either system pressure or from a mechanical closing force. If we divide the valves into two categories most ball valves and solid slab gate valves fall into the category that seals by means of system pressure, […]
Double block & bleed: understanding a barrier, part one.
Double block & bleed: understanding a barrier, part one. There are a lot of misunderstandings with regards to the meaning of the phrases double block & bleed, double isolation, double active seal or double barrier. Double block and bleed in accordance to API means that there is pressure on both sides of the valve but […]
Floating ball valves are more than just floating ball valves Part 3
As explained in parts 1 and 2 of this article series, the auxiliary valve fitted into the body of the valve can be very important if we are to create double sealing for a particular work situation, or if we want to test the seats/ball for tightness. The auxiliary valve can also come in handy […]
Floating ball valves are more than just floating ball valves: Part 2
When floating seats are used in a floating ball valve, they can be one of two basic designs. They can either be self-relief seats, as illustrated in fig. 5, or double piston seats, as illustrated in fig. 6. Regardless of which solution is used, the main seal of the valve will be its downstream […]
Floating ball valves are more than just floating ball valves Part 1
Floating ball valves are usually considered to be a simple type of valve and are not, in fact, particularly appreciated. When one talks about floating ball valves, most people think of a valve with fixed seats and a floating balls usually smaller valves inrelatively low pressures systems. Similar to the valve illustrated in fig. […]
What happens when oil and gas prices fall?
At first glance, the answer is simple: If the income of oil companies falls, there have to be cutbacks on spending – in short, they need to save money in every area. This can result in the outsourcing of services, cutting down of manpower and maintenance, and achieving a stronger price control as far as […]
The great globe valve / gate valve misunderstanding
The great globe valve / gate valve misunderstanding Normally when testing a new pipe system, the pipe and valves undergo initial testing that consists of two leak tests, a 150% hydrostatic test and an N2He leak test. These tests not only test the flanges connecting the valve to the pipe, but also test the […]
Do end-users really care about fugitive emission, or do they only want cheaper valves? Part 4
Do end-users really care about fugitive emission, or do they only want cheaper valves? Part 4 In the first part of this article I asked the following question: Is the situation different to day, then back in the 90´s? The answer was: Yes and No. One of the things I did not mention, witch […]
Do end-users really care about fugitive emission, or do they only want cheaper valves? Part 3
Do end-users really care about fugitive emission, or do they only want cheaper valves? Part 3 So what about high density die formed graphite packings? To answer that, we have to take a look back into the last part of this article. The main issue to get a good seal is contact between the […]
Do end-users really care about fugitive emission, or do they only want cheaper valves? Part 2
Do end-users really care about fugitive emission, or do they only want cheaper valves? Part 2 The braided packings are to be cut to fit the packing groove, whereas the die-formed are produced as finished rings. The Graphite packings can be high density, hard rings that can be compressible within 10-12% of its thickness, […]
Do end-users really care about fugitive emission, or do they only want cheaper valves? Part 1
Do end-users really care about fugitive emission, or do they only want cheaper valves? Part 1 May be this is a provocative questions, it´s ment to be. In the resent years there have been written miles by miles with articles and recommendations, there have been preformed tests and there have been developed new product, […]
Why I dislike NPT threads in a hydrocarbon system. Part two.
Ingolf Fra Holmslet has worked as a consultant and valve instructor in Norway since 1985. He has been responsible for the valve-training program for Statoil for the last 25 years. Why I dislike NPT threads in a hydrocarbon system. Part two. As we discussed in the last issue, it can be difficult from […]
Why I dislike NPT threads in a hydrocarbon system. Part one.
Ingolf Fra Holmslet has worked as a consultant and valve instructor in Norway since 1985. He has been responsible for the valve-training program for Statoil for the last 25 years. Why I dislike NPT threads in a hydrocarbon system. Part one. There are many reasons why NPT (National Pipe Taper) threads are not […]