Podcast
Questions and Answers
EASY What is the purpose of having multiple boilers in a larger steam system?
EASY What is the purpose of having multiple boilers in a larger steam system?
What happens when a boiler is cut in?
What happens when a boiler is cut in?
What do steam headers in multiple boiler systems conduct?
What do steam headers in multiple boiler systems conduct?
What type of header operates at 10 000 kPa?
What type of header operates at 10 000 kPa?
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Why must headers and piping be properly warmed up?
Why must headers and piping be properly warmed up?
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What occurs if headers and piping are not correctly warmed up?
What occurs if headers and piping are not correctly warmed up?
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Who should be in control of header warm-up procedures?
Who should be in control of header warm-up procedures?
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What is a characteristic of steam heating boilers?
What is a characteristic of steam heating boilers?
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Why are bypass valves used in the steam piping system?
Why are bypass valves used in the steam piping system?
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What is the purpose of the drains located at the non-return valves and header block valves?
What is the purpose of the drains located at the non-return valves and header block valves?
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What is the primary function of the non-return valves in the steam piping system?
What is the primary function of the non-return valves in the steam piping system?
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When warming up a boiler using header steam, what should be done with the boiler's non-return valve?
When warming up a boiler using header steam, what should be done with the boiler's non-return valve?
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What is the purpose of the header block valve bypass valve?
What is the purpose of the header block valve bypass valve?
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When is a boiler ready to be cut-in to the steam header?
When is a boiler ready to be cut-in to the steam header?
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What is the purpose of comparing the pressure on the main steam header to the pressure of the steam line to the boiler?
What is the purpose of comparing the pressure on the main steam header to the pressure of the steam line to the boiler?
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What should be done with the non-return valve drain during warm-up?
What should be done with the non-return valve drain during warm-up?
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Why is it important to remove condensate from the steam lines during warm-up?
Why is it important to remove condensate from the steam lines during warm-up?
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What is the purpose of the ASME Section VII 101.3.4 procedure?
What is the purpose of the ASME Section VII 101.3.4 procedure?
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What happens to the non-return valve when the boiler pressure exceeds the header pressure?
What happens to the non-return valve when the boiler pressure exceeds the header pressure?
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What is the purpose of initially restricting the opening of the non-return valve?
What is the purpose of initially restricting the opening of the non-return valve?
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What is the first step in the method of cutting in a boiler?
What is the first step in the method of cutting in a boiler?
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When can the Boiler 2 non-return drain valve be shut?
When can the Boiler 2 non-return drain valve be shut?
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What happens to the non-return valve as Boiler 2 pressure continues to rise?
What happens to the non-return valve as Boiler 2 pressure continues to rise?
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What is important to be familiar with prior to cutting in additional heating boilers?
What is important to be familiar with prior to cutting in additional heating boilers?
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How should the boiler stop valve be opened in the absence of a non-return valve?
How should the boiler stop valve be opened in the absence of a non-return valve?
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What is the function of the drain valve in Figure 3?
What is the function of the drain valve in Figure 3?
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When placing a steam heating boiler on line with other boilers, what should be done first?
When placing a steam heating boiler on line with other boilers, what should be done first?
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Why is it important to open the drain valve between the stop valve at the boiler outlet and the steam main?
Why is it important to open the drain valve between the stop valve at the boiler outlet and the steam main?
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What is the final step in the method of cutting in a boiler?
What is the final step in the method of cutting in a boiler?
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What should be done when the pressure within the boiler is approximately the same as the pressure in the steam main?
What should be done when the pressure within the boiler is approximately the same as the pressure in the steam main?
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What should be done with the drain valves at all system low points in a multiple boiler plant?
What should be done with the drain valves at all system low points in a multiple boiler plant?
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What is the purpose of the double block and bleed arrangement in Figure 3(b)?
What is the purpose of the double block and bleed arrangement in Figure 3(b)?
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When warming up a boiler in a multiple boiler plant, what should be done with the boiler stop valve and the header stop valve?
When warming up a boiler in a multiple boiler plant, what should be done with the boiler stop valve and the header stop valve?
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What is the purpose of Method One: Warming Boiler Header?
What is the purpose of Method One: Warming Boiler Header?
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Why is it hazardous to put a steam pipe into full service without warming it up and drying it out?
Why is it hazardous to put a steam pipe into full service without warming it up and drying it out?
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What should be done after the header and interconnecting piping are fully up to pressure and temperature?
What should be done after the header and interconnecting piping are fully up to pressure and temperature?
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What is the purpose of having multiple boilers in a steam system?
What is the purpose of having multiple boilers in a steam system?
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What is the purpose of a 10 000 kPa header in a steam plant?
What is the purpose of a 10 000 kPa header in a steam plant?
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Why is it crucial to warm up headers and piping in a steam plant?
Why is it crucial to warm up headers and piping in a steam plant?
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MEDIUM Who should be in control of header warm-up procedures in a steam plant?
MEDIUM Who should be in control of header warm-up procedures in a steam plant?
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What is a characteristic of steam heating boilers in a multiple boiler plant?
What is a characteristic of steam heating boilers in a multiple boiler plant?
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What happens when a boiler is cut-in to a steam header?
What happens when a boiler is cut-in to a steam header?
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What is the purpose of having multiple headers in a steam plant?
What is the purpose of having multiple headers in a steam plant?
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What is the consequence of not correctly warming up and draining headers and piping?
What is the consequence of not correctly warming up and draining headers and piping?
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What should be done with the boiler stop valve and the return stop valve when placing a steam heating boiler on line with other heating boilers that are already in service?
What should be done with the boiler stop valve and the return stop valve when placing a steam heating boiler on line with other heating boilers that are already in service?
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Why should the drain valve between the stop valve at the boiler outlet and the steam main be opened?
Why should the drain valve between the stop valve at the boiler outlet and the steam main be opened?
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What is the purpose of opening the drain valves at all system low points in a multiple boiler plant?
What is the purpose of opening the drain valves at all system low points in a multiple boiler plant?
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What is the purpose of the double block and bleed arrangement in Figure 3(b)?
What is the purpose of the double block and bleed arrangement in Figure 3(b)?
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What should be done with the stop valve for Boiler A when warming up the interconnecting steam piping?
What should be done with the stop valve for Boiler A when warming up the interconnecting steam piping?
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Why is it hazardous to put a steam pipe into full service without warming it up and drying it out?
Why is it hazardous to put a steam pipe into full service without warming it up and drying it out?
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What should be done with the boiler stop valve and the header stop valve when warming up a boiler in a multiple boiler plant?
What should be done with the boiler stop valve and the header stop valve when warming up a boiler in a multiple boiler plant?
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When can a boiler be considered ready to be cut-in to the steam header?
When can a boiler be considered ready to be cut-in to the steam header?
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What is the purpose of warming up the interconnecting steam piping in a multiple boiler plant?
What is the purpose of warming up the interconnecting steam piping in a multiple boiler plant?
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What should be done with the non-return valve drain during warm-up?
What should be done with the non-return valve drain during warm-up?
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What is the purpose of opening the non-return valve 25% during the initial phase of cutting in a boiler?
What is the purpose of opening the non-return valve 25% during the initial phase of cutting in a boiler?
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What happens when the boiler pressure exceeds the header pressure in a non-return valve?
What happens when the boiler pressure exceeds the header pressure in a non-return valve?
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What is the purpose of equalizing the pressure between the boiler and header stop valves using the header stop valve bypass?
What is the purpose of equalizing the pressure between the boiler and header stop valves using the header stop valve bypass?
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What is the correct sequence of steps when cutting in a boiler without a non-return valve?
What is the correct sequence of steps when cutting in a boiler without a non-return valve?
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What is the purpose of the drain valves located at the non-return valves and header block valves?
What is the purpose of the drain valves located at the non-return valves and header block valves?
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When can the boiler be considered fully on line?
When can the boiler be considered fully on line?
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What is the purpose of slowly opening the boiler stop valve in the absence of a non-return valve?
What is the purpose of slowly opening the boiler stop valve in the absence of a non-return valve?
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What should be done when the pressure within the boiler is approximately the same as the pressure in the steam main?
What should be done when the pressure within the boiler is approximately the same as the pressure in the steam main?
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What is the primary purpose of the bypass valves located at the header block valves?
What is the primary purpose of the bypass valves located at the header block valves?
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When warming up a boiler using steam from the header, what should be done with the boiler's non-return valve?
When warming up a boiler using steam from the header, what should be done with the boiler's non-return valve?
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What is the significance of comparing the pressure on the main steam header to the pressure of the steam line to the boiler?
What is the significance of comparing the pressure on the main steam header to the pressure of the steam line to the boiler?
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Why is it important to remove condensate from the steam lines during warm-up?
Why is it important to remove condensate from the steam lines during warm-up?
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What is the primary function of the non-return valves in the steam piping system?
What is the primary function of the non-return valves in the steam piping system?
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What happens to the non-return valve when the boiler pressure exceeds the header pressure?
What happens to the non-return valve when the boiler pressure exceeds the header pressure?
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What is the purpose of the drains located at the non-return valves and header block valves?
What is the purpose of the drains located at the non-return valves and header block valves?
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When is a boiler ready to be cut-in to the steam header?
When is a boiler ready to be cut-in to the steam header?
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Why is it important to open the drain valve slowly during warm-up?
Why is it important to open the drain valve slowly during warm-up?
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What is the purpose of the ASME Section VII 101.3.4 procedure?
What is the purpose of the ASME Section VII 101.3.4 procedure?
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What is the primary purpose of having a high-pressure header, an intermediate-pressure header, and a low-pressure header in a multiple boiler plant?
What is the primary purpose of having a high-pressure header, an intermediate-pressure header, and a low-pressure header in a multiple boiler plant?
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What is the potential consequence of not warming up headers and piping correctly in a multiple boiler plant?
What is the potential consequence of not warming up headers and piping correctly in a multiple boiler plant?
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Who should be in control of header warm-up procedures in a multiple boiler plant?
Who should be in control of header warm-up procedures in a multiple boiler plant?
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HARD What is a characteristic of steam heating boilers in a multiple boiler plant?
HARD What is a characteristic of steam heating boilers in a multiple boiler plant?
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What is the primary purpose of having multiple boilers in a steam system?
What is the primary purpose of having multiple boilers in a steam system?
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What is the purpose of having multiple headers in a steam plant?
What is the purpose of having multiple headers in a steam plant?
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What happens when a boiler is cut-in to a steam header?
What happens when a boiler is cut-in to a steam header?
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Why is it crucial to warm up headers and piping in a steam plant?
Why is it crucial to warm up headers and piping in a steam plant?
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What is the primary purpose of initially restricting the opening of the non-return valve?
What is the primary purpose of initially restricting the opening of the non-return valve?
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What happens when the boiler pressure exceeds the header pressure?
What happens when the boiler pressure exceeds the header pressure?
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What is the purpose of opening the bypass on the header stop valve?
What is the purpose of opening the bypass on the header stop valve?
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When can the boiler non-return valve be fully opened?
When can the boiler non-return valve be fully opened?
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In the absence of a non-return valve, how should the boiler stop valve be opened?
In the absence of a non-return valve, how should the boiler stop valve be opened?
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What is the purpose of the drain valves located at the non-return valves and header block valves?
What is the purpose of the drain valves located at the non-return valves and header block valves?
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What happens when the non-return valve sticks in the closed position?
What happens when the non-return valve sticks in the closed position?
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What is the final step in the method of cutting in a boiler?
What is the final step in the method of cutting in a boiler?
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What is the primary purpose of using bypass valves in the steam piping system?
What is the primary purpose of using bypass valves in the steam piping system?
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What is the significance of comparing the pressure on the main steam header to the pressure of the steam line to the boiler?
What is the significance of comparing the pressure on the main steam header to the pressure of the steam line to the boiler?
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What is the purpose of restricting the initial opening of the non-return valve?
What is the purpose of restricting the initial opening of the non-return valve?
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What is the consequence of not correctly warming up and draining headers and piping?
What is the consequence of not correctly warming up and draining headers and piping?
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When can a boiler be cut-in to the steam header?
When can a boiler be cut-in to the steam header?
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What is the purpose of the drain valves located at the non-return valves and header block valves?
What is the purpose of the drain valves located at the non-return valves and header block valves?
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What is the purpose of opening the drain valves at all system low points in a multiple boiler plant?
What is the purpose of opening the drain valves at all system low points in a multiple boiler plant?
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What is the purpose of the header block valve bypass valve?
What is the purpose of the header block valve bypass valve?
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Why is it crucial to warm up headers and piping in a steam plant?
Why is it crucial to warm up headers and piping in a steam plant?
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What is the purpose of Method One: Warming Boiler Header?
What is the purpose of Method One: Warming Boiler Header?
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What is the primary purpose of warming up a steam header in a multiple boiler plant?
What is the primary purpose of warming up a steam header in a multiple boiler plant?
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When warming up a boiler in a multiple boiler plant, what should be done with the boiler stop valve and the header stop valve?
When warming up a boiler in a multiple boiler plant, what should be done with the boiler stop valve and the header stop valve?
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What is the purpose of the drain valve between the stop valve at the boiler outlet and the steam main?
What is the purpose of the drain valve between the stop valve at the boiler outlet and the steam main?
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When should the boiler stop valve be fully opened?
When should the boiler stop valve be fully opened?
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What is the purpose of the double block and bleed arrangement in Figure 3(b)?
What is the purpose of the double block and bleed arrangement in Figure 3(b)?
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Why is it important to open the drain valves at all system low points in a multiple boiler plant?
Why is it important to open the drain valves at all system low points in a multiple boiler plant?
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What should be done when the pressure within the boiler is approximately the same as the pressure in the steam main?
What should be done when the pressure within the boiler is approximately the same as the pressure in the steam main?
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What is the purpose of Method One: Warming Boiler Header?
What is the purpose of Method One: Warming Boiler Header?
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Why is it hazardous to put a steam pipe into full service without warming it up and drying it out?
Why is it hazardous to put a steam pipe into full service without warming it up and drying it out?
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What should be done after the header and interconnecting piping are fully up to pressure and temperature?
What should be done after the header and interconnecting piping are fully up to pressure and temperature?
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Study Notes
Multiple Boiler Systems
- Multiple boilers are used to provide additional thermal capacity and ensure standby capacity is available when needed.
- Each boiler can be brought online from a cold start, firing from cold while the entire system is hot and at normal operating pressure.
Steam Headers
- Steam headers conduct steam from boilers to other equipment in the plant.
- Large and complex high-pressure steam plants can have multiple headers, identified by their operating pressures.
- Examples of headers include:
- High-Pressure Header (10 000 kPa) for high-pressure turbines and processes.
- Intermediate Pressure Header (2500 kPa) for intermediate-pressure turbines and processes.
- Low-Pressure Header (100 kPa) for steam heating and auxiliary equipment.
Header Warm-up Procedures
- Headers and piping must be properly warmed up to avoid thermal stress and remove condensate as it forms.
- Incorrect warm-up procedures can lead to severe water hammer during plant startup.
- In multiple boiler or multiple header plants, header warm-up procedures can be complex and must be performed under the control of a competent Power Engineer.
Cutting in Boilers
- Cutting in a boiler involves bringing it online and connecting it to the steam header.
- There are different warm-up procedures for boilers, depending on whether all boilers have been shut down or if some boilers are already online.
- Common procedures for warming up boilers include:
- Opening drain valves at all system low points to discharge condensate as steam lines warm up.
- Warming up the steam line to the header using steam from the boiler or the header.
- Using bypass valves to warm up the steam line to the boiler.
- Ensuring the boiler and header are at the same pressure and temperature before cutting in the boiler.
Specific Procedures for Cutting in Boilers
- Method One: Warming Boiler Header
- Open drain on non-return valve.
- Slightly open header valve to allow steam to flow from the header into the boiler steam line.
- Open header valve fully when the pressure has equalized between the steam header and boiler steam line.
- Method Two: Warming Boiler Header
- Open drain on non-return valve.
- Open header block valve drain.
- Open non-return valve about 25%.
- Slowly open header block valve bypass valve to warm up the steam line to the boiler.
- Permit drains to blow until the header and interconnecting piping are fully up to pressure and temperature.
Cutting in Boilers with Non-Return Valves
- Cut-in the boiler when the boiler steam line to the header and the steam header are up to temperature, and their pressures are equal.
- Method One: Cutting in a Boiler
- Open non-return valve about 25% when the boiler pressure is still a few kPa below the header pressure.
- Backing off on the stem of the non-return valve permits it to automatically open as the boiler pressure exceeds the header pressure.
- Open non-return valve fully when the boiler is supplying steam and there are no unusual conditions.
- Method Two: Cutting in a Boiler
- Open drain valves and non-return valve 25%.
- Warm up the boiler steam line using the header steam.
- Open bypass on header stop valve.
- Cut in the boiler to the header when the steam line is at temperature and pressure.
- Close drain valves and open header stop valve fully.
Cutting in Boilers without Non-Return Valves
- In this situation, the boiler does not have non-return valves, but rather conventional OS&Y rising stem valves.
- The boiler stop valve should be opened slowly when the pressures in the boiler, header, and steam line from the boiler are approximately equal.
- Equalize the pressure between the boiler and header stop valves using the header stop valve bypass.
- When the header pressure equals the boiler steam line pressure, the header stop valve can be slowly opened fully and its drain shut.
Multiple Boiler Systems
- Multiple boilers are used to provide additional thermal capacity and ensure standby capacity is available when needed.
- Each boiler can be brought online from a cold start, firing from cold while the entire system is hot and at normal operating pressure.
Steam Headers
- Steam headers conduct steam from boilers to other equipment in the plant.
- Large and complex high-pressure steam plants can have multiple headers, identified by their operating pressures.
- Examples of headers include:
- High-Pressure Header (10 000 kPa) for high-pressure turbines and processes.
- Intermediate Pressure Header (2500 kPa) for intermediate-pressure turbines and processes.
- Low-Pressure Header (100 kPa) for steam heating and auxiliary equipment.
Header Warm-up Procedures
- Headers and piping must be properly warmed up to avoid thermal stress and remove condensate as it forms.
- Incorrect warm-up procedures can lead to severe water hammer during plant startup.
- In multiple boiler or multiple header plants, header warm-up procedures can be complex and must be performed under the control of a competent Power Engineer.
Cutting in Boilers
- Cutting in a boiler involves bringing it online and connecting it to the steam header.
- There are different warm-up procedures for boilers, depending on whether all boilers have been shut down or if some boilers are already online.
- Common procedures for warming up boilers include:
- Opening drain valves at all system low points to discharge condensate as steam lines warm up.
- Warming up the steam line to the header using steam from the boiler or the header.
- Using bypass valves to warm up the steam line to the boiler.
- Ensuring the boiler and header are at the same pressure and temperature before cutting in the boiler.
Specific Procedures for Cutting in Boilers
- Method One: Warming Boiler Header
- Open drain on non-return valve.
- Slightly open header valve to allow steam to flow from the header into the boiler steam line.
- Open header valve fully when the pressure has equalized between the steam header and boiler steam line.
- Method Two: Warming Boiler Header
- Open drain on non-return valve.
- Open header block valve drain.
- Open non-return valve about 25%.
- Slowly open header block valve bypass valve to warm up the steam line to the boiler.
- Permit drains to blow until the header and interconnecting piping are fully up to pressure and temperature.
Cutting in Boilers with Non-Return Valves
- Cut-in the boiler when the boiler steam line to the header and the steam header are up to temperature, and their pressures are equal.
- Method One: Cutting in a Boiler
- Open non-return valve about 25% when the boiler pressure is still a few kPa below the header pressure.
- Backing off on the stem of the non-return valve permits it to automatically open as the boiler pressure exceeds the header pressure.
- Open non-return valve fully when the boiler is supplying steam and there are no unusual conditions.
- Method Two: Cutting in a Boiler
- Open drain valves and non-return valve 25%.
- Warm up the boiler steam line using the header steam.
- Open bypass on header stop valve.
- Cut in the boiler to the header when the steam line is at temperature and pressure.
- Close drain valves and open header stop valve fully.
Cutting in Boilers without Non-Return Valves
- In this situation, the boiler does not have non-return valves, but rather conventional OS&Y rising stem valves.
- The boiler stop valve should be opened slowly when the pressures in the boiler, header, and steam line from the boiler are approximately equal.
- Equalize the pressure between the boiler and header stop valves using the header stop valve bypass.
- When the header pressure equals the boiler steam line pressure, the header stop valve can be slowly opened fully and its drain shut.
Multiple Boiler Systems
- Multiple boilers are used to provide additional thermal capacity and ensure standby capacity is available when needed.
- Each boiler can be brought online from a cold start, firing from cold while the entire system is hot and at normal operating pressure.
Steam Headers
- Steam headers conduct steam from boilers to other equipment in the plant.
- Large and complex high-pressure steam plants can have multiple headers, identified by their operating pressures.
- Examples of headers include:
- High-Pressure Header (10 000 kPa) for high-pressure turbines and processes.
- Intermediate Pressure Header (2500 kPa) for intermediate-pressure turbines and processes.
- Low-Pressure Header (100 kPa) for steam heating and auxiliary equipment.
Header Warm-up Procedures
- Headers and piping must be properly warmed up to avoid thermal stress and remove condensate as it forms.
- Incorrect warm-up procedures can lead to severe water hammer during plant startup.
- In multiple boiler or multiple header plants, header warm-up procedures can be complex and must be performed under the control of a competent Power Engineer.
Cutting in Boilers
- Cutting in a boiler involves bringing it online and connecting it to the steam header.
- There are different warm-up procedures for boilers, depending on whether all boilers have been shut down or if some boilers are already online.
- Common procedures for warming up boilers include:
- Opening drain valves at all system low points to discharge condensate as steam lines warm up.
- Warming up the steam line to the header using steam from the boiler or the header.
- Using bypass valves to warm up the steam line to the boiler.
- Ensuring the boiler and header are at the same pressure and temperature before cutting in the boiler.
Specific Procedures for Cutting in Boilers
- Method One: Warming Boiler Header
- Open drain on non-return valve.
- Slightly open header valve to allow steam to flow from the header into the boiler steam line.
- Open header valve fully when the pressure has equalized between the steam header and boiler steam line.
- Method Two: Warming Boiler Header
- Open drain on non-return valve.
- Open header block valve drain.
- Open non-return valve about 25%.
- Slowly open header block valve bypass valve to warm up the steam line to the boiler.
- Permit drains to blow until the header and interconnecting piping are fully up to pressure and temperature.
Cutting in Boilers with Non-Return Valves
- Cut-in the boiler when the boiler steam line to the header and the steam header are up to temperature, and their pressures are equal.
- Method One: Cutting in a Boiler
- Open non-return valve about 25% when the boiler pressure is still a few kPa below the header pressure.
- Backing off on the stem of the non-return valve permits it to automatically open as the boiler pressure exceeds the header pressure.
- Open non-return valve fully when the boiler is supplying steam and there are no unusual conditions.
- Method Two: Cutting in a Boiler
- Open drain valves and non-return valve 25%.
- Warm up the boiler steam line using the header steam.
- Open bypass on header stop valve.
- Cut in the boiler to the header when the steam line is at temperature and pressure.
- Close drain valves and open header stop valve fully.
Cutting in Boilers without Non-Return Valves
- In this situation, the boiler does not have non-return valves, but rather conventional OS&Y rising stem valves.
- The boiler stop valve should be opened slowly when the pressures in the boiler, header, and steam line from the boiler are approximately equal.
- Equalize the pressure between the boiler and header stop valves using the header stop valve bypass.
- When the header pressure equals the boiler steam line pressure, the header stop valve can be slowly opened fully and its drain shut.
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Description
This quiz assesses understanding of non-return valves and their operation in boiler systems, including pressure control and flow management.