MN HP Piping Code Midterm Review

Flashcards prepared from the Minnesota High Pressure Piping Code Midterm Exam covering piping requirements, safety valves, weld specifications, expansion, and support spacing.

High pressure steam is defined as a pressure in excess of what value?

$$15\,\text{psig}$$

What is the pressure requirement for a hydrostatic test of a power piping system after erection?

$$1.5 \times \text{MAWP}$$

When are two blowoff valves required on a boiler and its appurtenances?

When the pressure exceeds $100\,\text{psig}$ (must have a slow opening valve).

What is the minimum internal diameter required for instrument tubing?

$$0.36\,\text{inch}$$

What is the maximum deviation above the S value allowed on power piping systems?

$$20\%$$

What is an example of an essential variable in a Welding Procedure Specification (WPS)?

Type of filler material

In order for a certified welder to qualify to a new Welding Procedure Specification wherein one or more essential variables are changed, what test must be performed?

A new WPQ (Welder Performance Qualification)

For high pressure boilers and piping, safety valves must discharge at a point of safety not less than what distance from running boards, platforms, or adjacent areas?

Not less than $7\,\text{feet}$

What is the safe maximum load at $650\,^\circ\text{F}$ of a $5/8\,\text{inch}$ ASTM A36 threaded rod?

$$2,160\,\text{lb}$$

What is the maximum span between supports without concentrated loads for a $12\,\text{inch}$ standard steam branch line?

$$30\,\text{feet}$$

What are the two requirements concerning water discharge from a blowdown tank before entering a drain?

1. Pressure must be less than $5\,\text{psig}$ 2. Temperature must be less than $140\,^\circ\text{F}$

List the three types of guided bend test specimens.

1. Side bend 2. Face bend 3. Root bend

Heating media piping systems are understood to include fluids used for heating when pressure and temperature exceed what limits?

Pressure exceeds $30\,\text{psig}$ and temperature exceeds $250\,^\circ\text{F}$

According to the notes, a qualification test for a Weld Procedure Specification shall be in accordance with which code section?

ASME Section II

Welding on piping directly attached to an ASME Section I boiler up to a functional boundary valve requires what stamp?

PP Stamp

What is the allowable percent increase of stress on hangers for short time overloading conditions?

$$20\%$$

How much will a $2\,\text{inch}$ copper line expand given an installation temperature of $65\,^\circ\text{F}$, operating temperature of $378\,^\circ\text{F}$, and length of $80\,\text{feet}$?

$2\frac{7}{8}\,\text{inch}$ (or $2.854\,\text{inch}$)

What is the definition of stress relieving?

Pipe is brought to required temperature, held at that temperature for a period of time, and then cooled slowly.

Are economizers, heaters, tanks, and other pressure vessels inside or outside the scope of the code?

They are outside the scope of the code, but connecting piping shall conform to the requirements.

What does the acronym OS&Y stand for?

Outside Screw and Yoke

Up to what temperature limit may copper pipe or tubing be used on steam systems?

Provided the temperature is not above $406\,^\circ\text{F}$

What percent of total calculated expansion would you cut the pipe short when constructing and installing an expansion loop?

$$50\%$$

What is the outer diameter (OD) of a $10\,\text{inch}$ Class 300 weldneck flange?

$$17\frac{1}{2}\,\text{inch}$$

What is the maximum span between supports without concentrated loads for a $4\,\text{inch}$ extra heavy wall steam branch line?

$$15\,\text{feet}$$

By what methods shall thermal expansion of piping be compensated?

Pipe bends, offsets, expansion loops, and changes in direction

How many safety valves are required for each boiler with over $500\,\text{square feet}$ of water heating surface?

Two or more safety valves

When boilers are connected to a common steam main, what shall the steam connection from each boiler having a manhole opening be fitted with?

Fitted with 2 stop valves and a free blow drain between them

What is the requirement regarding two means of feeding water to a boiler fired by solid fuel?

They cannot be subject to the same type of interruption.