Process Safety Built Into Every Field Job

PHA, PSSR, and MOC for Field-Deployed Process Equipment

At DHI, process safety is not reserved for permanent plants, major facilities, or large capital projects. We apply process safety discipline to field-deployed equipment projects because mobile and temporary systems can carry the same operational risks as fixed infrastructure.

Every field job involving process equipment is reviewed through a practical safety framework built around:

  • Process Hazard Analysis, PHA

  • Pre-Startup Safety Review, PSSR

  • Management of Change, MOC

This approach helps ensure that each job is properly scoped, reviewed, installed, started up, operated, and modified under controlled conditions.

Our Commitment

DHI is committed to applying process safety discipline to every field-deployed process equipment project.

Whether the job involves a single pump package or a complex SCADA-controlled water treatment system, the same principle applies:

Every job must be understood before it is started. Every startup must be verified before operation. Every change must be reviewed before implementation.

That is how DHI delivers field process equipment projects with safety, reliability, and accountability.

Temporary Equipment Still Requires Permanent Discipline

Field-deployed systems are often assembled quickly, in difficult environments, and under changing customer requirements. A water treatment package, transfer pump system, chemical injection skid, tank battery, DAF unit, hose system, or SCADA-controlled process may be temporary, but the hazards are real.

These systems can involve:

  • Pressure

  • Flow restriction

  • Overfill risk

  • Chemical exposure

  • Hydrocarbons

  • H2S exposure

  • Oil carryover

  • Solids loading

  • Pump failure

  • Power loss

  • Control failure

  • Spill potential

  • Operator error

  • Environmental exposure

DHI’s position is simple:

A temporary system should never be treated as an informal system.

If equipment is moving fluid, applying pressure, injecting chemicals, separating oil, handling solids, or operating under PLC or SCADA control, it must be reviewed with discipline before operation begins.

Our Standard for Every Job

For every field-deployed process equipment project, DHI applies a structured review process.

1. Scope the Job

Before equipment is mobilized or started, we define the work clearly.

This includes:

  • What the customer is trying to achieve

  • What fluid is being handled

  • What equipment will be used

  • What the expected flow rates are

  • What pressures may be created

  • What chemicals may be required

  • What tanks, hoses, pumps, and manifolds are involved

  • What control systems are needed

  • What alarms, shutdowns, or safeguards are required

  • What operating limits must be followed

The objective is to understand the system before it is placed in service.

2. Perform a Process Hazard Analysis

DHI reviews the process before startup to identify potential issues.

The PHA considers:

  • Loss of flow

  • Blocked discharge

  • Closed valves

  • Pump deadhead

  • Tank overflow

  • Incorrect valve alignment

  • Chemical overfeed

  • Chemical underfeed

  • Loss of containment

  • Unexpected oil or solids loading

  • H2S or vapor exposure

  • Pressure buildup

  • Hose or manifold failure

  • Control system failure

  • Loss of SCADA communication

  • Power interruption

  • Restart after shutdown

  • Operator misunderstanding

The PHA identifies hazards, consequences, safeguards, and action items required before startup.

The goal is not paperwork. The goal is to make sure the equipment, operating plan, and field team are ready for the real conditions they may face.

3. Close Safety and Readiness Action Items

Before startup, required action items must be addressed.

These may include:

  • Adding pressure gauges

  • Installing high-level alarms

  • Confirming shutdown logic

  • Revising hose routing

  • Adding containment

  • Changing valve placement

  • Updating operating procedures

  • Confirming chemical compatibility

  • Improving access for maintenance

  • Testing instrumentation

  • Training operators

  • Clarifying emergency response steps

  • Correcting equipment deficiencies

No job should proceed simply because the equipment has arrived on location. The system must be made ready.

4. Complete a Pre-Startup Safety Review

The PSSR is the final readiness gate before operation.

DHI verifies that:

  • The installed equipment matches the approved setup

  • The flow path is correct

  • Pumps, tanks, hoses, valves, and manifolds are properly configured

  • Pressure ratings are suitable

  • Chemical systems are correctly installed and labeled

  • Controls and instrumentation are functioning

  • SCADA displays are active where required

  • Alarms and shutdowns have been checked

  • Operators understand the system

  • Procedures are available

  • Emergency response steps are understood

  • PHA action items are closed or formally approved

The PSSR confirms that the job is not just assembled, but ready to operate safely.

5. Start Up Under Controlled Conditions

Startup is one of the highest-risk points in field operations.

DHI starts process systems in a controlled manner, with attention to:

  • Initial flow rate

  • Pressure response

  • Tank level behavior

  • Chemical dosing rates

  • Pump performance

  • Valve positions

  • Instrumentation readings

  • SCADA visibility

  • Alarm response

  • Operator communication

  • Customer interface points

  • Early signs of instability

The system is closely monitored during initial operation to correct issues before they become incidents.

6. Manage Changes Through MOC

Field conditions change. DHI recognizes that adjustments are sometimes necessary. However, changes must be reviewed before implementation.

Management of Change applies when there are changes to:

  • Equipment selection

  • Pump capacity

  • Hose size or routing

  • Tank sequence

  • Valve arrangement

  • Manifold configuration

  • Chemical type

  • Chemical dosing rate

  • Operating pressure

  • Flow rate

  • PLC logic

  • Alarm settings

  • Shutdown settings

  • SCADA screens

  • Bypass lines

  • Tie-in pointS

  • Operating procedures

  • Staffing or operating responsibility

The purpose of MOC is to prevent uncontrolled field changes from creating new hazards.

Before a material change is made, DHI reviews:

  • What is changing

  • Why the change is needed

  • What new hazards may be created

  • Whether pressure, flow, chemistry, containment, or controls are affected

  • Whether procedures must be updated

  • Whether operators need additional instruction

  • Whether the PHA must be revised

  • Whether a new PSSR is required before the restart

This keeps the job under control even as operating conditions evolve.