An orbital GTAW head will make the root welds on 2-inch 316L sanitary tube in a food plant. What must be done inside the tube before and during welding?

Purge it with argon behind dams until an O2 analyzer reads low

Flow CO2 from a GMAW cylinder through it

Nothing; the torch gas shields both sides of the joint

Blow it out with shop air to cool the root

You are working from the top flange of an I-beam 25 ft (7.6 m) above a boiler-room floor, wearing a full-body harness and a 6-ft (1.8 m) shock-absorbing lanyard. Where should the lanyard be connected?

To a rated anchor at or above your dorsal D-ring

Choked back on itself around the beam flange

To a beam clamp at your foot level on the flange

Around the 2-inch steam line running above the beam

Field measurements show that a new 6-inch chilled-water line, routed as drawn on the isometric, would pass through the web of an existing structural beam. What is the correct course of action?

Hold that section and submit an RFI through your supervisor

Cut a sleeve hole through the beam web and install as drawn

Reroute it around the beam and show it on the as-builts

Install it as drawn up to the beam and cap it there

You will use an articulating boom lift to reach a valve on an overhead pipe rack in an oil-sands module yard. What fall protection applies while you are in the platform?

Harness, lanyard clipped to the platform's anchor point

Harness, lanyard clipped to the rack you are working on

Harness worn, lanyard left unclipped for movement

None; the platform guardrails give full protection

A process line in a refinery must be isolated by double block and bleed before a flange is broken. What does that arrangement consist of?

Two closed valves with an open bleed valve between them

One closed valve with a spectacle blind swung to closed

Two closed valves with the space between them pressurized

One closed valve with a drain opened just downstream

Red Seal 307A Safety, Tools & Welding Practice Questions

Five free practice questions on safety, tools and welding: block A of the Red Seal 307A Steamfitter/Pipefitter exam, about 16 of its 130 questions. They are in the exam's format: four options, one correct answer. Answer each one before opening the explanation. No account, no email.

01The questions

Procedural · Uses welding equipment

An orbital GTAW head will make the root welds on 2-inch 316L sanitary tube in a food plant. What must be done inside the tube before and during welding?
1. Flow CO2 from a GMAW cylinder through it
2. Purge it with argon behind dams until an O2 analyzer reads low
3. Nothing; the torch gas shields both sides of the joint
4. Blow it out with shop air to cool the root
Show the answer

B. Correct. The inside of a stainless root is shielded by an argon purge held in by purge dams; flow continues until an oxygen analyzer shows the level the WPS requires, and throughout welding. Without it the root oxidizes (sugaring), ruining corrosion resistance and the sanitary finish.

Why not the others

A. CO2 is an active gas; it oxidizes the root and adds carbon to low-carbon stainless. The purge gas for 316L is argon (or what the WPS allows).

C. Torch shielding gas covers the face of the weld only. On a full-penetration stainless joint the root side needs its own purge.

D. Shop air contains oxygen and moisture, the very things that oxidize the back of the weld. A stainless root needs an inert purge, not air.
Procedural · Uses personal protective equipment (PPE) and safety equipment

You are working from the top flange of an I-beam 25 ft (7.6 m) above a boiler-room floor, wearing a full-body harness and a 6-ft (1.8 m) shock-absorbing lanyard. Where should the lanyard be connected?
1. Choked back on itself around the beam flange
2. To a rated anchor at or above your dorsal D-ring
3. To a beam clamp at your foot level on the flange
4. Around the 2-inch steam line running above the beam
Show the answer

B. Correct. Anchoring overhead (at or above the back D-ring) keeps free fall short and lowers the arrest force. The anchor must be rated for fall arrest per the regulation (commonly 22 kN / 5000 lb per worker), with enough clearance below for lanyard, deceleration distance and body length.

Why not the others

A. Choking a standard lanyard around a beam with sharp edges can cut it, and tie-back use is allowed only with a lanyard designed and rated for it. Use a proper beam anchor or anchor strap.

C. Anchoring at foot level adds up to 6 ft (1.8 m) of free fall before the lanyard starts working, raising the arrest force and the clearance needed. Anchor at or above the D-ring.

D. Piping is not a rated anchor: a small line can fail or tear out its hangers under arrest loads, and a hot line can damage the lanyard. Only engineered or rated anchor points are used.
Procedural · Interprets drawings and specifications

Field measurements show that a new 6-inch chilled-water line, routed as drawn on the isometric, would pass through the web of an existing structural beam. What is the correct course of action?
1. Hold that section and submit an RFI through your supervisor
2. Cut a sleeve hole through the beam web and install as drawn
3. Reroute it around the beam and show it on the as-builts
4. Install it as drawn up to the beam and cap it there
Show the answer

A. Correct. A conflict between the drawings and the site is documented (measurements, photos, drawing references) and sent as a request for information so the engineer issues a resolution or revised drawing. Work continues elsewhere meanwhile.

Why not the others

B. Structural members are not cut or drilled by the piping trade without the structural engineer's approval; it could weaken the building.

C. Recording the change afterwards skips the approval step. A reroute can affect supports, pressure drop, clearances and other trades, so the engineer decides before the pipe is changed.

D. Building up to a known conflict wastes material and time and may have to be undone. Raise the discrepancy first.
Procedural · Uses access equipment

You will use an articulating boom lift to reach a valve on an overhead pipe rack in an oil-sands module yard. What fall protection applies while you are in the platform?
1. Harness, lanyard clipped to the rack you are working on
2. Harness worn, lanyard left unclipped for movement
3. Harness, lanyard clipped to the platform's anchor point
4. None; the platform guardrails give full protection
Show the answer

C. Correct. In an articulating or telescopic boom, wear a full-body harness with a short lanyard (travel restraint preferred) connected to the manufacturer's anchor in the platform. Operators also need MEWP training for the unit.

Why not the others

A. Tying off to structure outside the basket is dangerous: if the boom moves or drives, the worker can be pulled out of the platform. Connect only to the platform's designated anchor.

B. An unclipped lanyard gives no protection. The lanyard stays connected to the platform anchor whenever the platform is raised or moving.

D. In a boom lift the platform can bounce or catapult, throwing a worker over the rails. A harness and lanyard are required in booms (per the regulation and the manufacturer), even where scissor lifts rely on guardrails.
Recall · Follows lock-out and tag-out (LOTO) procedures

A process line in a refinery must be isolated by double block and bleed before a flange is broken. What does that arrangement consist of?
1. One closed valve with a spectacle blind swung to closed
2. Two closed valves with the space between them pressurized
3. Two closed valves with an open bleed valve between them
4. One closed valve with a drain opened just downstream
Show the answer

C. Correct. Two block valves in series are closed and the bleed between them is opened to a safe location, so anything passing the first seat is vented instead of reaching the second. Watching the bleed also proves whether the first valve is holding.

Why not the others

A. A valve plus a blind is positive isolation by blinding, a different method on the RSOS list. Double block and bleed uses two valves and a bleed, with no blind.

B. Pressurizing the cavity is a sealing technique, not double block and bleed. The bleed must be open to show and relieve any leakage past the upstream seat.

D. That is a single block and bleed. It relies on one seat; if the valve passes, product flows straight to the work.

02Answer key

Question	Answer	Sub-task
Q1	B	Uses welding equipment
Q2	B	Uses personal protective equipment (PPE) and safety equipment
Q3	A	Interprets drawings and specifications
Q4	C	Uses access equipment
Q5	C	Follows lock-out and tag-out (LOTO) procedures

03What block A covers

This block covers the shop and site skills behind every other task. It includes WHMIS labels, fall protection, confined-space air, lockout and double block and bleed, ladders and scaffolds, powder-actuated tools and grinders, welding electrodes and purging, soldering and brazing, oxy-fuel and plasma cutting, isometrics, spool sheets and piping specs, takeoffs, flange bolting, NDE and mentoring apprentices.

The Red Seal Occupational Standard names this block “Performs common occupational skills”. It carries 12.3% of the exam, about 16 of the 130 questions, split across four tasks. The share column is each task's weight within the block, as the standard publishes it.

Task and its sub-tasks	Share of block
Performs safety-related functions Maintains safe work environment; Uses personal protective equipment (PPE) and safety equipment; Follows lock-out and tag-out (LOTO) procedures	27%
Uses and maintains tools and equipment Uses common tools and equipment; Uses access equipment; Uses welding equipment; Uses soldering and brazing equipment; Uses oxy-fuel and plasma cutting equipment	37%
Organizes job Plans work; Generates drawings; Interprets drawings and specifications; Develops piping templates; Performs quality control functions; Handles materials and components	23%
Uses communication and mentoring techniques Uses communication techniques; Uses mentoring techniques	13%

04What the questions turn on

Proving isolation

Notify, shut down, isolate, lock and tag, release stored energy, then verify with a try-start and a gauge at zero with the drain open. Pressure rising past one closed valve means it is passing, so add a second valve and bleed or a blind.

Oxy-fuel rules

Acetylene is never drawn above 15 psig, where it can decompose violently. On a flashback, shut the torch oxygen valve first, then the fuel. Fuel hose is red with left-hand, notched nuts; oxygen hose is green with right-hand threads.

Soldering, brazing and purging

A filler that melts below 450 °C (840 °F) is soldering; above that it is brazing. Copper to steel takes a BAg silver alloy with flux. A low flow of dry nitrogen through copper while brazing stops oxide scale forming inside.

Reading the drawings

A spool sheet details one shop piece; field welds between spools are marked FW. The piping class in a line number points to the spec for material, schedule, flange rating and gaskets. A mitre cut angle is the total turn divided by twice the welds.

05The other blocks

The 307A exam has seven blocks. Each has its own page of free questions:

The 307A Steamfitter/Pipefitter practice exam page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.